6. [-/1 Points] DETAILS OSUNIPHYS1 7.2.P.048. MY A 6.0 kg body has eight times the kinetic energy of a 7.5 kg body. Calculate the ratio of the speeds of these bodies. V6.0 kg _ V7.5 kg + Additional Materials Reading MY NC 7. [-/2 Points] DETAILS OSUNIPHYS1 7.2.WA.014. An athlete with a mass of 67 5 cross country race and at one instant he has a sneed of 5 40 m/c DEC V+ Additional Materials Reading 4. [-/1 Points] DETAILS OSUNIPHYS1 7.1.P.038. MY NOTES ASK YOUR It takes 375 J of work to compress a spring 24 cm. What is the force constant of the spring (in kN/m)? KN/m + Additional Materials Reading MY NOTES ASK YOUR TE 5. [-/1 Points] DETAILS OSUNIPHYS1 7.2.P.044. DEC 5 at tv 419. [-/2 Points] DETAILS OSUNIPHYS1 7.4.P.073. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) How long (in s) will it take an 870 kg car with a useful power output of 44.0 hp (1 hp = 746 W) to reach a speed of 11.0 m/s, neglecting friction? (Assume the car starts from rest.) (b) How long (in s) will this acceleration take if the car also climbs a 2.60 m-high hill in the process? Additional Materials Reading DETAILS OSUNIPHYS1 7.4.P.077. MY NOTES ASK YOUR TEACHER PRACTICE ANOTH 20. [-/2 Points] DEC W G 5 . - as tv022 | WebAssign 9. [-/2 Points] DETAILS OSUNIPHYS1 7.3.P.060. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A 3.0 kg block starts with a speed of 15 m/s at the bottom of a plane inclined at 410 to the horizontal. The coefficient of sliding friction between the block and plane is /k = 0.24. (a) Use the work-energy principle to determine how far (in m) the block slides along the plane before momentarily coming to rest. m (b) After stopping, the block slides back down the plane. What is its speed (in m/s) when it reaches the bottom? (Hint: For the round trip, only the force of friction does work on the block.) m/s Additional Materials Reading PRACTICE ANOTHER MY NOTES ASK YOUR TEACHER OSUNIPHYS1 7.3.P.062. 10. [-/2 Points] DETAILS A small block of mass 230 g starts at rest at A, slides to B where its speed is Vg = 8.2 m/s, then slides along the horizontal surface a distance 16 m before coming to rest at C. (See below.) 4 G DEC as tv 5C Courses Wh Ch. 7 Homework - PHYS-2425, section 51102, Fall 2022 | WebAssign 15. [-/3 Points] DETAILS OSUNIPHYS1 7.3.WA.025. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER An object starts from rest at the origin and moves along the x axis subject to the force shown in the figure below. If the mass of the object is 63.0 kg, determine the speed of the object at the following positions. Each unit along the position axis is 4.00 m and each unit along the force axis is 3.00 N. F (N) x(m) C (a) x = A m/s (b) x = B m/s (c) x = C m/s Additional Materials Readingwork - PHYS-2425, section 51102, Fall 2022 | Web Scale records tension Additional Materials Reading 14. [-/2 Points] DETAILS OSUNIPHYS1 7.3.WA.024. MY NOTES ASK YOUR TEACHER An object with a mass of m = 2.50 kg is traveling with an initial velocity of v; = (5.201 - 1.20j) m/s. (a) Determine its initial kinetic energy. (Give your answer to at least one decimal place.) (b) Determine the amount of work that must be done on the object in order to change its velocity to v = (6.001 + 7.00j) m/s. Additional Materials Reading MY NOTES ASK YOUR TEACHER 15. [-/3 Points] DETAILS OSUNIPHYS1 7.3.WA.025. An object starts from rest at the origin and moves along the x axis subject to the force shown in the figure below. If the mass of the object is 63.0 kg, determine the spee unit along the force axis is 3.00 N.Additional Materials Reading 17. [-/1 Points] DETAILS OSUNIPHYS1 7.4.P.069. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHE A large household air conditioner may consume 14.0 KW of power. What is the cost of operating this air conditioner 3.50 h per day for 20.0 d if the cost of electricity is $0.170 per kW.h? $ + Additional Materials Reading MY NOTES ASK YOUR TEACHER PRACTICE ANOTHE 18. [-/2 Points] DETAILS OSUNIPHYS1 7.4.P.071. W G DEC 5 as tv[-IS Points] OSUNIPHYS'! 7.3.WA.019.TUTORIAL. At the time :1 = 0, an object with a mass m = 4,01 kg passes through the origin with a velocity 31 = (5.611 2.413) mls. At a ti Assume that the force acting on the object dun'ng the time interval At = t2 - t1 ls constant and determine the following. l ' (a) the kinetic energy of the object at the time :1 J (b) the force acting on the object during the time interval At = t2 tl (Express ynur answer in vector form.) (c) the work done on the object by the force during the time interval At = t2 :1 J (d) the kinetic energy of the object at the time t2 J (e) the speed of the object at the time t2 A Ch. 7 Homework - PHYS-2425, section 51102, Fall 2022 | WebAssign Reading 16. [-/2 Points] DETAILS OSUNIPHYS1 7.4.P.067. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A person in good physical condition can put out 100 W of useful power for several hours at a stretch, perhaps by pedaling a mechanism that drives an electric generator. Neglecting any problems of generator efficiency and practical considerations such as resting time, answer the following. (a) How many people would it take to run a 4.00 KW electric clothes dryer? people (b) How many people would it take to replace a large electric power plant that generates 600 MW? people Additional Materials Reading PRACTICE ANOTHER MY NOTES ASK YOUR TEACHER 17. [-/1 Points] DETAILS OSUNIPHYS1 7.4.P.069. A large household air conditioner may consume 14.0 KW of power. What is the cost of operating this air conditioner 3.50 h per day for 20.0 d if the cost of electricity is $0.170 per kW.h? 4 W DEC atv 5Additional Materials Reading 5. [-/1 Points] DETAILS OSUNIPHYS1 7.2.P.044. MY NOTES ASK Compare the kinetic energy of a 22,000 kg truck moving at 105 km/h with that of an 83.0 kg astronaut in orbit moving at 26,500 km/h. KEtruck KE astronaut + Additional Materials Reading 6. [-/1 Points] DETAILS OSUNIPHYS1 7.2.P.048. MY NOTES ASK speeds of these bodies.hange by what factor? K ; Additional Materials Reading 8. [-/1 Points] DETAILS OSUNIPHYS1 7.2.WA.016. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER The center fielder for the school's baseball team throws a 0.150-kg baseball towards home plate at a speed of 21.9 m/s and an initial angle of 40.0. What is the kinetic energy of the baseball at the highest point of its trajectory? Additional Materials Reading ASK YOUR TEACHER PRACTICE ANOTHER MY NOTES 9. [-/2 Points] DETAILS OSUNIPHYS1 7.3.P.060. A 3.0 kg block starts with a speed of 15 m/s at the bottom of a plane inclined at 410 to the horizontal. The coefficient of sliding friction between the block and plane is My = 0.24. T A W G DEC astv 5 MacBook ProReading [-/1 Points] DETAILS OSUNIPHYS1 7.4.P.080. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Coal is lifted out of a mine a vertical distance of 49 m by an engine that supplies 430 W to a conveyor belt. How much coal per minute can be brought to the surface? Ignore the effects of friction. (Enter your answer in kg/min.) kg/min + Additional Materials Reading Submit Assignment Save Assignment Progress G tv20. [-/2 Points] DETAILS OSUNIPHYS1 7.4.P.077. MY NOTES A man of mass 77 kg runs up a flight of stairs 19 m high in 57 s. (a) How much power (in W) is used to lift the man? W (b) If the man's body is 25% efficient, how much power does he expend (in W)? W + Additional Materials Reading MY NOTE DETAILS OSUNIPHYS1 7.4.P.080.. . G webassign.net C Courses WA Ch. 7 Homework - PHYS-2425, section 51102, Fall 2022 | WebAssign 11. [-/1 Points] DETAILS OSUNIPHYS1 7.3.P.064. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER When released from rest, a 200 g block slides down the path shown below, reaching the bottom with a speed of 3.4 m/s. How much work does the force of friction do (in ])? 3.1 m 3.4 m/s X Additional Materials Reading MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER 12. [-/5 Points] DETAILS OSUNIPHYS1 7.3.WA.019.TUTORIAL. At the time t, = 0, an object with a mass m = 4.01 kg passes through the origin with a velocity v, = (5.61i - 2.41j) m/s. At a time to = 2.00 s, the object is at the position r = (8.001 + 4.00j) m. that the force acting on the object during the time interval At = t2 - t, is constant and determine the following.022 | WebAssign 10. [-/2 Points] DETAILS OSUNIPHYS1 7.3.P.062. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A small block of mass 230 g starts at rest at A, slides to B where its speed is Vg = 8.2 m/s, then slides along the horizontal surface a distance 16 m before coming to rest at C. (See below.) 4.0 m B -16 m (a) What is the work of friction along the curved surface (in ])? (b) What is the coefficient of kinetic friction along the horizontal surface? HK = Additional Materials Reading G DEC 9 518. [-/2 Points] DETAILS OSUNIPHYS1 7.4.P.071. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) What is the average useful power output (in W) of a person who does 6.60 x 10 ] of useful work in 8.40 h? W (b) Working at this rate, how long (in s) will it take this person to lift 2100 kg of bricks 1.40 m to a platform? (Work done to lift his body can be omitted because it is not considered useful output here.) Additional Materials Reading Q W G DEC 5 MacBook Pro.. . C webassign.net Courses My Ch. 7 Homework - PHYS-2425, section 51102, Fall 2022 | WebAssign 13. [-/1 Points] DETAILS OSUNIPHYS1 7.3.WA.023. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A toy plane with a mass of 0.850 kg is tied to a string and made to travel at a speed of 21.0 m/s in a horizontal circle with a 17.0-m radius. The person holding the string pulls the plane in, increasing the tension in the string, increasing the speed of the plane and decreasing the radius of the plane's orbit. What is the net work done on the plane if the tension in the string increases by a factor of four and the radius decreases to 12.0 m. ON Newtons (N) Scale records tension Additional Materials Reading7. [-/2 Points] DETAILS OSUNIPHYS1 7.2.WA.014. MY NOTES An athlete with a mass of 67.5 kg is in a cross country race, and at one instant he has a speed of 5.40 m/s. (a) What is his kinetic energy at this instant? K = (b) If he wishes to doubles his speed to reach the finish line, his kinetic energy will change by what factor? KF Additional Materials Reading MY NOTES 8. [-/1 Points] DETAILS OSUNIPHYS1 7.2.WA.016. The center fielder for the school's baseball team throws a 0.150-kg baseball towards home plate at a speed of 21.9 m/s and an initial angle. . . D G webassign.net Courses W Ch. 7 Homework - PHYS-2425, section 51102, Fall 2022 | WebAssign 3. [-/3 Points] DETAILS OSUNIPHYS1 7.1.P.033. MY NOTES ASK YOUR TEACHER PRACTICE ANOT A 5.1 kg box rests on a horizontal surface. The coefficient of kinetic friction between the box and surface is ux = 0.50. A horizontal force pulls the box at constant velocity for 32 cm. (a) Find the work done (in J) by the applied horizontal force. (b) Find the work done (in ]) by the frictional force. (c) Find the work done (in ]) by the net force. Additional Materials Reading MY NOTES ASK YOUR TEACHER PRACTICE ANOT 4. [-/1 Points] DETAILS OSUNIPHYS1 7.1.P.038. W G