Physics Questions and Answers November 20, 2022

A small puck of mass m and speed v0slides on a frictionless table and collides with a barbell(total mass2M),as shown in the figure. The barbell, which is free to rotate about a fixed axle through its center, is initially at rest. The length of the barbell is d.The puck and the barbell stick together after contact. Consider the system consisting of

m VO velcro (M) (M) fixed pivot point

What is the length of the shadow of a vertical straight rod of the length l, if the incident sunrays form an angle of 45 with the Earth surface?

Consider a model room represented by a cubical box with all sides having a length of 36 cm. Since it is a cube, Ly Ly L, meaning f100 f010 foo1. a) Calculate the first five acoustic modes in order of ascending frequency. b) Such resonances might be undesirable. What are three ways they they could be minimized

A frictionless object is dropped from a height of 20.0 m at the same time that another frictionless object if thrown vertically upwards with a speed of 18.0 m/s. Where will the objects meet with respect to the ground?

The force of attraction that a 46 C point charge exerts on a 100 C point charge has magnitude 3.00 N. How far apart (in m) are these two charges (k 14 8.99 10 NmC)

A ball of mass m 1 =5 kg travels to the right with a velocity of v 1 =10 m/s. It impacts a stationary ball of mass m 2 =5 kg. After the collision, the second ball is now moving to the right with a velocity of v 2 =8 m/s. Calculate the velocity of the first ball after the collision.

The lowest string on a guitar is 63.5 cm long and tuned to the note E (329.64 Hz). The string has a linear density of 1.07x10-3 kg/m. How much tension must be on the string if the string is vibrating at the fundamental frequency?

A furnace is at a temperature of 600 kelvins. Calculate the change in entropy of the furnace when 2800 J of heat energy is transferred from the furnace to the environment.

A crate has an applied force of 60N applied to push it to the left at 3 m/s 2 . What is it's mass? The friction force is 15N.

The value of specific heat for copper is 390 J/kgC , for aluminum is 900 J/kg C , and for water is 4186 J/kg C, What will be the equilibrium temperature when a 275 g block of copper at 255 C is placed in a 145 g aluminum calorimeter cup containing 855 g of water at 13.0 C ?

You design a transmitter in your engineering lab to radiate a sinusoidal signal in all directions. the transmitter has an average total power of 50.0 kW. find the electric field amplitude in V/m at a distance 70.0 km away from the emitting sources.

A capacitor is connected to an AC source. If the maximum current in the circuit is 0.580 A and the voltage from the AC source is given by Av (90.2 V) sin(60)st, determine the following. (a) the rms voltage (in V) of the source V (b) the frequency (in Hz) of the source Hz (c) the capacitance (in F) of the capacitor F

An inductor is connected to an AC source. If the inductance of the inductor is 0.524 H and the output voltage of the source is given by Av (120 V)sin(32.0 s )t, determine the following. (a) the frequency of the source (in Hz) Hz (b) the rms voltage across the inductor (in V) V (c) the inductive reactance of the circuit (in ) Q (d) the rms current

a) Find the rms current in each bulb. b) Find the resistance of each bulb. c) What is the total resistance of the combination of the three lightbulbs?

The figure below shows three lightbulbs connected to a 120V AC (rms) household supply voltage. Bulbs 1 and 2 have a power rating of 120 W, and bulb 3 has a 40W rating. 120 V 3 o boboto 1

A massless spring with spring constant 18 N/m is attached to a ball, and both hang from the ceiling at rest. The ball is then pulled down 8 cm and released. If the ball makes 35 oscillations in 12 s, what are the ball's: a. period? b. mass? c. maximum speed

A simple pendulum consists of a 0.6 kg mass attached to a 2.5 m long string, and is oscillating in simple harmonic motion. a. What is the period of the pendulum if the mass is doubled b. What is the period of the pendulum if the length of the string is doubled c. If the pendulum is moved to the moon, where the acceleration due to gravity is 1.6

An infinitely long solid cylinder (u 1) of radius R oriented along the zaxis is carrying a constant current density Jo jo(s)ez, where jo(s) (Rs) here (r) is the Heaviside step function, which is 0 if x 0 and 1 if x 0. Calculate the magnetic vector potential A and magnetic field inside and outside of the cylinder. To do so proceed as

(a) What is the lowest possible frequency emitted by the speakers? (b) What is the lowest possible frequency emitted by the speakers, if the two speakers are out of phase?

Two speakers S and S are 10 m apart. The speakers emit sound of the same frequency and are in phase with each other. A person standing at point P hears a maximum (constructive interference) in sound level. S 10 m S 12 m P

The half-life of helium-6 is 806.7 ms. If helium-6 is placed in a particle accelerator and is travelling at 99.855% of the speed of light, what half-life will a scientist measure?

A plane lands on a runway and undergoes constant deceleration, coming to a complete stop after 10.0s in a distance of 300m.Calculate the rate of deceleration.

Light with a wavelength of 2.00x 10 -7 m is directed at a metallic surface made of yttrium, which has a work function of 3.11 eV. With what speed will photoelectrons be produced, and what is the cut-off potential necessary to stop the photoelectrons?

A designer is working on a new roller coaster, and she begins by making a scale model. In this model ,a car of total mass m=0.5kg moves with negligible friction along the track shown. The car is given an initial speed v0 = 1/5 m/s at the top of the first hill of height 2 m. Point A is located at a height of 1.9 m at the top of the second hill, the

0.50 kg 2.0 m 1.5 ms r0.95 m 1.9 m,0.50 kg 2.0 m 1.5 ms r0.95 m 1.9 m

An ice cube of dimensions 1.00 cm x 1.00 cm x 1.00 cm floats on water. The densities of ice 3 and water are pice 0.917 g cm and water 1.00 g cm respectively. Assume constant accel eration due to gravity g 9.81 m s. (a) (6 marks) Find the depth d of the ice cube sub merged in water at equilibrium. (b) (14 marks) The ice cube is perturbed verti

Two springs of spring constants k and k are con nected to either side of a block of mass m. The block lies on a frictionless horizontal surface. For simplicity, assume that both springs are at the nat ural lengths at the equilibrium position. Let x be the displacement of the block from the equilibrium position. (a) (4 marks) Draw a free body

The International Space Station, which has a mass of 4.7110 5 kg, orbits 244 miles above the Earth's surface, and completes one orbit every 91.4 minutes. What is the kinetic energy of the International Space Station in units of GJ (1099 Joules)? (Note: the radius of the Earth : r (Earth} = 3959 miles)

A 5.00-kg crate is sitting on the ground at rest. An electric motor with an efficiency of 0.20 (20%) is used to raise a crate up by a height of 2.0 meters so that it has an upward velocity of 4.0 m/s as it reaches that height. Calculate the electrical energy consumed by the motor during this process.

Rod 1, with a thermal conductivity of 442 WmK, rod 2, with a thermal conductivity of 150 WmK, and rod 3, with a thermal conductivity of 125 WmK, are placed end to end with rod 2 between the other two. The rods have the same length and the same diameter. The free end of rod 1 is maintained at waters boiling point, and the free end of rod 3 is

A plug-in transformer supplies 9.00 V to a video game system. (a) How many turns are in its secondary coil if its input voltage is 120 V and the primary coil has 333 turns? (b) What is its input current when its output is 1.15 A

A 7.30 F capacitor and a 3.80 mH inductor are connected in series with an AC power source that has a frequency of 1.20 x 103 Hz and a peak voltage of 58.0 V. Take the initial time t as zero when the instantaneous voltage equals zero. (a) What is the instantaneous voltage at t 1.26 x 104 s (b) Determine the instantaneous current when t 1.26 x 104

An RLC series circuit has a 193 2 resistor and a 25.0 mH inductor. At 8475 Hz, the phase angle is 45.0. (a) What is the impedance (b) Find the minimum possible capacitance of the circuit. nF

A 12.0 Hz,16.0 V source produces a 3.60 mA current when connected to a capacitor. What is the capacitance?

You wish to produce an emf of 43.0mV using an inductor whose inductance is 13.0H. You start with a current of 1.50 mA through the inductor and increase the current at a steady rate. What is the current through the inductor at the end of 3.00 s ?

The heating coils in a hair dryer are 0.800 cm in diameter, have a combined length of 1.00 m, and a total of 381 turns. (a) What is their total selfinductance assuming they act like a single solenoid H (b) What average emf opposes shutting them off if this is done in 4.17 ms (onefourth of a cycle for 60 Hz AC) and there is a current of 12.2 A

A voltage source is used to charge a 3.85F capacitor. The voltage source is then removed and the capacitor is connected in series with a 3.70mH inductance coil and a resistor R. What value of the resistor will result in critical damping of the oscillations

The current through a coil as a function of time is represented by the equation I(t) Aebt sin(wt), where A 5.25 A, b 1.75 x 102 s1, and w 375 rads. At t 0.670 s, this changing current induces an emf in a second coil that is close by. If the mutual inductance between the two coils is 4.38 mH, determine the induced emf. (Assume we are using a

Determine the wavelength of an electron with kinetic energy 2.0 eV. (a) 0.68 nm (b) 0.87 nm (c) 0.54 nm (d) 0.76 nm

of mass if the density is constant. 217121 Determine the coordinates of the center 2 a 2 12 NR

Calculate the gravitational force of a 50 kg mother who is holding her 5 kg child. Take the mother and the child to be particles that are 20 cm apart.

A model car is scaleddown version of the prototype. All dimensions are at a scale of 14 and will be tested in a water tunnel at 80F. Assuming that the prototype is used at the same temperature, in air, and at a velocity of 100 fts. Determine the velocity at which the water tunnel should be operated (15 points).

Consider the pulley system as shown in the picture. The blocks have a mass of 1.0 kg each. Suppose the pulley is massless and there is no friction. What is the tension in the rope when the blocks accelerate due to gravity only For the force on the left mass we can write F mgTma T m(ga) For the right mass this is F T ma. From there we finally

A car went 50 km to the south during 45 min and then 60 km to the east during 80 min. (30 pts.) a) What is the total displacement vector (start to end) describing its motion b) What is the average velocity vector (magnitude and direction) c) What is the average speed of the car,A steel ball is dropped from yo 70 m. At what height y is it expected

A) What is the ratio of the slit width to the wavelength of the incident light? B) What is the wavelength of the incident light, in nanometers? C) If the screen is very wide, how many dark bands appear to one side of the central maximum?

In a singleslit diffraction experiment, a coherent light source illuminates a slit in a barrier, and the resulting pattern is projected on a screen that is separated from the barrier by a distance which is very large as compared to the slit width and the wavelength of the light source. A light sensor is used to measure the intensity of the light

A 980 gr rock is whirled in a horizontal circle at the end of a 1.8 m long string. If the breaking strength of the string is 150 N, and at the minimum angle the string can make with the horizontal, what is the speed of rock? (g=9.8 m/s2) Group of answer choices 12.39 m/s 16.57 m/s 0 m/s 15.36 m/s 19.85 m/s

A heavy rope is tied to a light string. A transverse wave travels from the rope to the string. What is the same about the wave as it goes from one to the other?

The electronneutral collision cross section o for 1eV electrons in H can be approximated by a where ao 0.53x108cm is the radius of the first Bohr orbit of the hydrogen atom. A plasma column with no magnetic field has p 10 Torr of hydrogen at room temperature (20C) and Te 1 eV. (a) Compute the electron diffusion coefficient in ms, assuming that

If a copper ring has a 500mm diameter at 330C, what will its diameter (in mm) be after being dropped in 210C Liquid Nitrogen (Again, please only include the numerical value)

Why dont third law pairs cancel, even though they are equal but opposite A) because they invert each other. B) No one knows the answer. C) because they do not act upon a single object. D) friction is irreversible.

Two wires are in the shape of a plus sign. Each wire carries 10 A of current. What is the Total Magnetic field at point P,2 wire 1 wire 2 2m 5 m P

Some students will have difficulty getting their trunk off the group when starting from the legs straight with arms stretched above head sit-up position. Describe a way that students might cheat in order to complete this sit-up. Use the concept of torques (LINK BELOW) to explain why their strategy makes performing the sit-up easier.

byjus.comphysicstorque

A glass tube has three different cross sectional areas with the values indicated in the figure. A piston at the left end of the tube exerts pressure so that the mercury within the tube flows from the right end with a speed of 8.0 ms. Three points within the tube are labeled A, B and C. The atmospheric pressure is 1.01 x 105 Nm and the density of

A form of nonrenewable alternative energy can be: Oil Coal Geothermal Gas

When we enlarge a photograph of an iron ring, the image of the hole becomes a. smaller. b. neither smaller nor larger. c. larger.

The kinetic energy of a photoelectron depends on which one of the following ? Thesum of threshold frequency and frequency of incident light. The ratio of threshold frequency and frequency of incident light The difference of threshold frequency and frequency of incident light The intensity of incident light

How is artificial gravity created? A) rotational acceleration B) holodeck C) graviton waves (D) warp engines

A pendulum clock at high altitudes runs A) fast. B) slow. C) normally as it does at sea level.

A 35-cm-long icicle hangs from the eave of a house on a day when the temperature is -2.0C. By how many millimeters does the icicle shrink if a bitterly cold wind drops the temperature to -24 C Explain your answer.

0.485 cm3 of a gas at 579.88 kPa absolute, is cooled until the temperature is 51.4 oC. The resulting volume is 0.347 cm3 at a pressure of 402.19 kPa absolute. What was the initial temperature of the gas? Report your answer in oC, rounded to one decimal place. Units are not required for this answer

Which of the following are are sources of particles that contribute significantly to solar weather? A. solar flares B. sunspots C. prominences D. CMEs E. coronal holes F. plages

How much heat is released or absorbed when 2.50 moles of nitrogen dioxide is produced?

What is the acceleration due to gravity at a location where a 15-kilogram mass weighs 45 newtons? 1. 2. 9.81 m/s 3. 3.00 m/s 4. 0.333 m/s

A 106-g cube of ice at 0 c is dropped into 1 kg of water that was originally at 77 c,what is the final temperature of the water after the ice has been melted?

..A.29.0..kHz,.16.0. V source connected to an inductor produces a 3.60 A current. What is the inductance using Ohms law Review the definition of inductive reactance. H A 13.6 H inductor is connected to an AC source whose emf is represented by the equation E Emax sin(27ft) where max 38.5 V and f 40.0 Hz. Determine the amplitude of the current. mA

A nearsighted person needs a corrective lens that is divergent with a strength of 4 diopters. What is the farthest point she can see clearly without glasses a) 25 cm b) 30 cm c) 40 cm d) 45 cm

A nurse measures the temperature of a patient to be 41.4C. (a) What is this temperature on the Fahrenheit scale F (b) Do you think the patient is seriously ill (Assume the patient has a serious fever if the temperature is above 100F) O Yes O No Explain.

A man attaches a divider to an outdoor faucet so that water flows through a single pipe of radius 8.85 mm into three pipes, each with a radius of 5.00 mm. If water flows through the single pipe at 1.35 ms, calculate the speed (in ms) of the water in the narrower pipes. HINT 4.216 X ms

A horizontal pipe narrows from a radius of 0.240 m to 0.120 m. If the speed of the water is 1.70 ms in the smaller pipe, what is the speed in the larger pipe (in ms)

Tyler and Nick are showing off by lifting weights. Tyler lifts a 50 lb weight 15 times in 30 seconds while Nick lifts it 20 times in 30 seconds. Which statement about their work and power is correct Assume they move the weights the same distance each time they lift. They do the same work but Tyler has less power than Nick. They do the same work

A hotair balloon consists of a basket hanging beneath a large envelope filled with hot air. A typical hotair balloon has a total mass of 524 kg, including passengers in its basket, and holds 2.68 x 10 m of hot air in its envelope. If the ambient air density is 1.28 kgm, determine the density (in kgm) of hot air inside the envelope when the balloon

A sphygmomanometer is a device used to measure blood pressure, typically consisting of an inflatable cuff and a manometer used to measure air pressure in the cuff. In a mercury sphygmomanometer, blood pressure is related to the difference in heights between two columns of mercury. The mercury sphygmomanometer shown in the figure below contains air

A father is giving a ride to his little daughter. He can push or pull her sled with the same force and same angle as is depicted in the pictures. In with case he is doing more work (b) 0 (a) F,Case (a) as the friction is more. O Case (b) as the friction is less. In both cases he is doing the same work. We can not say until we have the angle.

A sealed cubical container 18.0 cm on a side contains. gas with two times Avogadros number of xenon atoms at a temperature of 30.0C. (a) Find the internal energy (in J) of the gas. 7254.63 X J (b) The total translational kinetic energy (in J) of the gas. (c) Calculate the average kinetic energy (in J) per atom. 1 ( ) ( 12mv ) t to calculate the

Two forces, of magnitudes F 100 N and F 50.0 N, act in opposite directions on a block, which sits atop a frictionless surface, as shown in the figure. (Figure 1 )Initially, the center of the block is at position a 2.00 cm. At some later time, the block has moved to the right, and its center is at a new position, f 6.00 cm. Find the work W done

Many aspects of a gymnasts motion can be modeled by representing the gymnast by four segments consisting of arms, torso (including the head), thighs, and lower legs, as in the figure below. 60 b Thigh Arm 10 Torso 60 Leg,In the figure, (b) shows arrows of lengths rc locating the center of gravity of each segment. Use the data below and the

An inductor and a resistor are connected in series with a battery via a switch. Initially, the switch is open. At t 0, the switch is closed. At t 65.8 ms, ()(der), dE dt DEL is the rate at which energy is stored in the magnetic field and dER is the rate at which energy is dissipated in the resistor. Find the time constant of this circuit. dt dt

A coil with 26 turns is connected in series with a resistor, a battery, and a switch. The battery has an emf of 13.5 V. Initially, the switch is open. At t 0, the switch is closed. When the current through the coil is 1.80 A, the flux through each individual turn of the coil is 2.70 x 104 T m. Find the time rate of change of current when t 1.45T.

Calculate the effects of the following pulse sequences on thermal equilibrium magnetization. The final answer should include x, y, and z components of magnetization. a) 90x (a pulse with tip angle 90, applied about the xaxis) b) 80x c) 90x90y (the second 90 pulse is applied immediately after the first)

A disk of mass M is spinning freely at 9.67 rads when a second identical disk, initially not spinning, is dropped onto it so that their axes coincide. In a short time the two disks are corotating. (a) What is the angular speed of the new system (in rads) rads (b) If a third such disk is dropped on the first two, find the final angular speed of the

A lab has created an electric field of 1.0106 Vm in the positive z direction, and a magnetic field of 0.50 T, which is at an angle of 45 to the positive y axis, in the direction of the positive z axis (B0.50(g222)). A particle is moving in those fields at a speed of 1.0 x 10 ms in the positive z direction. (a) What fields will the particle

Two identical spheres with masses M 5 kg and radii R 5 cm are attached to opposite ends of a thin L 6R 30 cm long horizontal rod of mass m 1 kg. The system has a pin at the center of the rod and can rotate around it in vertical plane, as seen in the figure. At some point you push the sphere on the right with a force of 3 N and the system

1. One mole of an ideal gas is held at a constant pressure of 1 atm. Find the change in volume (in liters) if the temperature changes by 50 C. 2. A container with a one-liter capacity at 27C is filled with helium to a pressure of 2.0 atm. (1 atm=1.0105 N/m 2 .) How many moles of helium does it hold?

A child of mass m sits on top of a rectangular slab of mass M=40 kg, which in turn rests on a frictionless horizontal floor. The slab is attached to a horizontal spring with spring constant k=400 N/m (the other end is attached to the wall), as seen in the figure. The coefficient of static friction between the child and the top of the slab is

X A M 0 A 0.40 k 450 Nm www

A Block of crown glass is immersed in water as in the figure shown below. A light ray is incident on the top face at an angle of 1=41.0 with the normal and exits the Block at point P (Assume that x=3.15 cm ). a. Find the vertical distance y from the top of the block to P. b. Find the angle of refraction of the light ray leaving the block at P.

In order to strengthen the arms, an athlete uses the following machine. Using the given velocity of handle, A, find velocity of weight B. Also, determine the magnitude of relative velocity of weight B with respect to velocity of point A. Velocity of point A is 0.5 ms to the left,In order to strengthen the arms, an athlete uses the following

A string is 600m long with a mass of 6.00 g. The string is held taut with a tension of 300.00 N applied to the string. A pulse is sent down the string. How long (in ms) does it take the pulse to travel the 600 m of the string ma Additional M

A car with a mass of 1500 kg is being towed by a rope held at a 20 angle to the horizontal. A friction force of 320 N opposes the car's motion. What is the tension in the rope if the car goes from rest to 12 m/s in 10 s ? (Answer must be in newtons.)

An arrow is placed at points A ( A is very far to the left of the lens), B, C, and F as shown on the figure (where F is the focal point of the convex lens). Using ray diagrams, determine where the image would form, and state if it is inverted or upright, and if it is real or virtual.

B F C F, B F C F

How long would it take (in seconds) to heat 215.2ml of water from 20C to 78.0C using a heater with a power rating of 50 W (i.e., it puts out 50 Joules of energy every second)? For water: use 334 kJ/kg for the latent heat of fusion, 2.26103 kJ/kg for the latent heat of vaporization, and 4.19 kJ/kgC for the specific heat. Also for water: remember

Consider the circuit shown, with L 0.25 H, L 0.40 H, R 490 2, R 370 2, R 560 N, and V9.0 V for the battery. Construct plots of the three currents as functions of time. Determine the moment when the total energy stored magnetically is equal to the total energy dissipated in resistance. R L www www (0000). R L www

Suppose a series circuit contains R125 92, C 17.0 F, and L 165 mH. (a) If this circuit is connected to a 120V 60.0 Hz source, what is the impedance Which element will have the largest peak voltage across it, and what will that voltage be Which will have the smallest voltage, and will it be (b) A source of what frequency will produce the same

A convex rearview car mirror has a radius of curvature of 16.0 cm. a. Determine the location of the image and its magnification for an object 10.0 cm from the mirror. b. What is the power of a 25.0cm focal length converging lens (in diopters)?

In the figure below are two lenses positioned such that the distance between them is D= 20.0 cm. The first lens (on the left) has a focal length of 10.0 cm, while the second lens has a focal length of 20.0 cm. If the object is placed 30.0 cm to the left of lens 1 , what is the location of the final image (d i2 ) and the combined magnification of

30.0 cm Object 20.0 cm i10.0 cm 20,0 cm

Four objects are held in position at the corners of a rectangle by light rods as shown in the figure below. (The mass values are given in the table.) m (kg) m (kg) m3 (kg) m4 (kg) 3.10 2.30 4.30 1.90 m m y 0 m 4.00 m 6.00 m x m (a) Find the moment of inertia of the system about the xaxis. kg. m (b) Find the moment of inertia of the system about

II BIO Pumping iron. A 72.0 kg weight lifter is doing arm raises using a 7.50 kg weight in her hand. Her arm pivots around the elbow joint, starting 40.0 below the horizontal. (See Figure 10.70.) Biometric measurements have shown that both forearms and the hands together account for 6.00 of a persons weight. Since the upper arm is held vertically,

A 440N uniform rectangular sign 4.00 m wide and 3.00 m high is suspended from a horizontal, 6.00mlong, uniform, 150N rod as indicated in the figure below. The left end of the rod is supported by a hinge and the right end is supported by a thin cable making a 30.0 angle with the vertical. (Assume the cable is connected to the very end of the

How does the internal energy of the ice and water mixture change if the temperature does not rise while the ice is melting It decreases, because you need to use energy to make a freezer run, but ice melts spontaneously. O It increases, because it takes more energy for water molecules to be disordered than to be ordered. It remains the same,

A cook holds a 1.70kg carton of milk at arm's length (see the figure below). What force FB must be exerted by the biceps muscle? (Ignore the weight of the forearm Give the magnitude.)

Milk THE to 25.0 cm 75.0 8.00 cm FA

Aartha is viewing a distant mountain with a telescope that has a 120cmfocal length objective lens and an eyepiece with a 2.0 cm focal length. she sees a bird that's 5.2m distant and wants to observe it. To do so, she has to refocus the telescope. By how far must she move the eyepiece in order to focus on the bird?

The arm in the figure below weighs 35.9 N. The force of gravity acting on the arm acts through point A. Determine the magnitudes of the tension force F, in the deltoid muscle and the force F exerted by the shoulder on the humerus (upperarm bone) to hold the arm in the position shown. (Enter your answers to at least the nearest newton.) Ft N Fe N