Pls answer all the questions according and to the best of your capabilities

Uniform Circular Motion Activity Sheet A6 Purpose: The purpose of this activity is to explore the characteristics of the motion of an object in a circle at a constant speed. Procedure and Questions: 1. Navigate to the Uniform Circular Motion page (httgs:[[wwwphysicsclassroom.cothhysics- InteractiveSZCircular-and-Satellite-MotionZUniform-Circular-Motion) and experiment with the on- screen buttons in order to gain familiarity with the control of the animation. The object speed, radius of the circle, and object mass can be varied by using the sliders or the buttons. The vector nature of velocity and acceleration can be depicted on the screen. A trace of the objects motion can be turned on, turned off and erased. The acceleration of and the net force acting upon the object are displayed at the bottom of the screen. The animation can be started, paused, continued or rewound. After gaining familiarity with the program, use it to answer the following questions: 2. Velocity is a vector quantity which has both magnitude and direction. Using complete sentences, describe the body's velocity. Comment on both the magnitude and the direction. 3. TRUE or FALSE? If an object moves in a circle at a constant speed, its velocity vector will be constant. Explain your answer. 4. In the diagram at the right, a variety of positions about a circle are shown. Draw the velocity vector at the various positions; direct the v arrows in the proper direction and label them as v. Draw the acceleration vector at the various positions; direct the a arrows in the proper direction and label them as a. A6 5. Describe the relationship between the direction of the velocity vector and the direction of the acceleration for a body moving in a circle at constant speed. 6. A Puzzling Question to Think About: If an object is in uniform circular motion, then it is accelerating towards the center of the circle; yet the object never gets any closer to the center of the circle. It maintains a circular path at a constant radius from the circle's center. Suggest a reason as to how this can be. How can an object accelerate towards the center Without ever getting any closer to the center? 7. A "Thought Experiment": Suppose that an object is moving in a clockwise circle (or at least trying to move in a circle). Suppose that at point A the object traveled in a straight line at constant speed towards B'. In what direction must a force be applied to force the object back towards B? Draw an arrow on the diagram in the direction of the required force. Repeat the above procedure for an object moving from C to D'. In what direction must a force be applied in order for the object to move back to point D along the path of the circle? Draw an arrow on the diagram. If the acceleration of the body is towards the center, what is the direction of the unbalanced force? Using a complete sentence, describe the direction of the net force which causes the body to travel in a circle at constant speed. A6 8. Thinking Mathematically: Explore the quantitative dependencies of the acceleration upon the speed and the radius of curvature. Then answer the following questions. a. For the same speed, the acceleration of the object varies (directly, inversely) with the radius of curvature. b. For the same radius of curvature, the acceleration of the object varies (directly, inversely) with the speed of the object. c. As the speed of an object is doubled, the acceleration is (onefourth, one-half, two times, four times) the original value. d. As the speed of an object is tripled, the acceleration is (one-third, one- ninth, three times, nine times) the original value. c. As the radius of the circle is doubled, the acceleration is (one-fourth, onehalf, two times, four times) the original value. f. As the radius of the circle is tripled, the acceleration is (onethird, one ninth, three times, nine times) the original value. Summary Statement: Write a conclusion to this lab in which you completely and intelligently describe the characteristics of an object that is traveling in uniform circular motion. Give attention to the quantities speed, velocity, acceleration and net force. A7 1. Describe an energy transformation that can be used to produce electrical energy. 2. A worker moves a box with a mass m along a warehouse oor. What variables determine the amount of work done on the box by the worker? Be specific. 3. Airbags are a type of safety device installed in vehicles to protect passengers from injury in a collision. a. Explain how energy transformations are used in airbags to protect passengers from injury during a collision. b. What are some of the limitations of airbags as a safety device? 4. Write the proportionality statement relating the variables that are defined in bold, and sketch the corresponding graph for each case. a. The gravitational potential energy of a person walking up a flight of stairs doubles when the height of the stairs doubles. b. The kinetic energy of a car depends on the square of its speed. c. The acceleration of a particle triples as the applied force increases by a factor of three. 5. Compare the costs and benefits of operating a laptop computer using its battery versus using an electrical outlet. Include at least one social impact, one environmental impact, and one economic impact. 6. A digital balance scale is often used to measure the mass of an object. What sources of error would you minimize when attempting to determine an object's mass? A8 1. An emergency worker applies a force of 16 N to push a patient horizontally for 2.5 m on a gurney with nearly frictionless wheels. Determine the work done in pushing the gurney if the force is applied: a. Horizontally b. at an angle of 25 below the horizontal 2. A woman pushes a lawnmower with a force of 150 N at an angle of 35 down from the horizontal. The lawn is 10 m wide and requires 15 complete trips across and back. How much work does she do? 3. A toboggan carrying several children (total mass = 100 kg) reaches its maximum speed at the bottom of a hill, and then glides 10 m along a horizontal surface before coming to a stop. The coefficient of kinetic friction between the toboggan and the snowy surface is 0.10. a. Draw a FBD of the toboggan when it is gliding to a stop. b. Determine the kinetic friction acting on the toboggan. 0. Calculate the work done by the kinetic friction. d. Why is the work done negative? 4. A student pushes against a large maple tree with a force of magnitude 250 N. How much work does the student do on the tree? 5. A 500 kg meteoroid is travelling through space far from any measureable force of gravity. If it travels at 100 m/s for 1000 years, how much work is done on the meteoroid? 6. A nurse holding a newborn 3.0 kg baby at a height of 1.2 m off the oor carries the baby 15 m at a constant velocity along a hospital corridor. How much work has the force of gravity done on the baby? 7. A hiker pulls a sled a distance 345 m with a constant force of 135 N exerted at an angle of 48. Friction acts on the sled with a constant force of 67.0 N. Calculate the work done on the sled by (i) the hiker and (ii) friction, and (iii) the total work done on the sled. A8 8. The graph shows the variation of applied force with displacement. Determine the work done by the force from: 8.0 3, so c' U ': 5.0 8.0 10.0 Position. [ml 2 direction of motion 4ofcrate a. 0-5m 4 \"3'3 Fl b. 5-8m c. 8-10m scale: 1.0 em = 5.0 N d. 0-10 m Figure 5 For question 1 . Figure 5 shows a scale diagram of two applied forces, i] and 752, acting on a crate and causing it to move horizontally. Which force does more work on the crate? Explain your reasoning. Can the work done by the force of kinetic friction on an object ever be positive? If "yes." give an example. lf"no." explain why not. Can the work done by the force of Earth's gravity on an object ever be positive? If "yes." give an example. If "no." explain why not. A 2.75kg potted plant rests on the floor. Determine the work required to move the plant at a constant speed (a) to a shelf 1.37 m above the floor (b) along the shelf for 1.07 m where the coefficient of kinetic friction is 0.549 A loaded grocery cart of mass 24.5 kg is pushed along an aisle by an applied force of 14.2 N [22.5 below the horizontal]. How much work is done by the applied force if the aisle is 14.8 m long? A tension force of 12.5 N [19.5 above the horizontal] does 225J of work in pulling a toboggan along a smooth. horizontal surface. How far does the toboggan move? A9 1. By what factor does a car's kinetic energy increase when the car's speed: a. doubles b. triples c. increases by 26% A whale with a mass of 15000 kg is swimming with a speed of 6.1 m/s. A nearby boat startles the whale, and the whale increases its speed to 12.8 m/s. Calculate the work done by the water on the whale. A police car of mass 2.4 x 103 kg is travelling on the highway when the officers receive an emergency call. They increase the speed of the car to 33 mls The increase in speed results in 3.1 x 105 J of work done on the car. Determine the initial speed of the police car in km/h. An archer pulls back her bowstring. loaded with a 22 g arrow, and then releases the string. If the arrow leaves the bowstring at a speed of 220 km/h, calculate the work done on the arrow by the bowstring. Two objects have the same kinetic energy. One has a speed that is 2.5 times the speed of the other. Determine the ratio of their masses. (Hint: assume v1 = 2.5v2) Understanding Concepts 1. As a net external force acts on a certain object. the speed of the object doubles. and then doubles again. How does the work done by the net force in the first doubling com- pare with the work done in the second doubling? Justify your answer mathematically. 3. (a) lithe velocity of the car in question 2 increases by 15.0%. what is the new kinetic energy of the car? Cb) By what percentage has the kinetic energy of the car increased? to) How much work was done on the car to increase its kinetic energy? 5. A basketball moving with a speed at 12 mls has a kinetic Figure '0 energy or as JA What is the mass of th - ball? Australian "road-trains" are massive transport trucks comprised . of three or more trailers hooked up together The long. flat desert roads of central Australia make this an ideal form for transporting goods. (at) Prepare a table to compare the kinetic energies of these two vehicles travelling at ever-increasing speeds. at the plate lust be are It hits the ro-r up to a maximum of 40.0 m/s. 7. A 81-kg skier. coasting down a hill that is at an angle of 23 (b) Prepare a single graph of kinetic energy as a function to the horizontal. experiences a force of kinetic friction of of speed, plotting the data for both vehicles an the magnitude 7.2 N. The skier's speed is 3.5 mi's near the top of same set of axes_ the slope. Determine the speed after the skier has travelled (c) Based on your calculations and the graph. write con- 52 m downhi'I- Air \"Sismnce \"3 "Eg'igib'e- clusions about the masses. speeds. and kinetic ener- ' ; . 1: lly gies of moving vehicles. .etfi ' \"(5 'Or ear-'5 1| on .y . . heard t 2 . ression ":.; d kill " '. discus sion 0 r-v'icacc'nt rom . - ys' spe :u: time- be a ex -ssio- r'ni- . be " etic ner-- ' ." \"PPM\"! '\"ql'iW 5""3 (a) W; -na affic ccid- ' invo in- 2 Ie t r e - dying a. The heaviest trucks in the world travel along relatively flat v-hic oco . l 2 initial .- ne ' en. - ft - roads in Australia. A fully loaded \"road-train\" [Figure a] e ole-(s) u ransfo i- 0 so e ing. a - - e . has a mass of 5.0 X 102 I. while a typical car has a mass of on thin - - energy ._ -.- ? -'/ abaut1.2t. (b) Explain eexpressio "Kineti nergy Ills."