1.in a moving object of mass 10kg through distance of 8.0 m, 40J of work is done The average force exerted is:A 5.0n B 80nC400nD 320nE 4.0n2.what is the kinetic energy of a 20kg object moving at a speed of 10m/s2A 2000JB 200 JC 100JD 500JE 1000J3the gravitational potential of a bird of a mass of 2.0kg on a tree branch height of 15 m is most nearly:A 3000JB 15JC3.0JD 300JE 30J4 two objects have the same mass one is traveling twice as fast as the other the work that must be done to stop the faster object compared to the work to stop the slower object is: A two times greater B one quarter as great C half as great D four time greater E the same 5 when a rock is thrower straight up in the air after it leaves the hand the rock begins to slow down this occurs because A the rock is gaining potential energy as it rises and thus must loose kinetic energy B the forces acting on the rock are balancedC the force of gravity acting on the rock increases as the rock rises D the potential energy of the rock decreases as the rock rises 6a 2.5kg mass at rest on a horizontal surface is acted upon by an applied horizontal force of 150 N a frictional force of 150N acts of the mass.How much work is done on the mass?A50JB 30JC 125 JD 0E 60 J7- mass of 10kg initally at rest on a horizontal frictionless surface is acted on upon by a horizontal force of 25N the speed of the mass after it has moved 5.0m is ?A125m/sB250m/sC10m/sD5.0m/sE15m/s8 a 100kg mass is dropped from a height of 3.0m the kinetic energy before striking the ground is A 30JB 3000J C300J D3.0JE0.30J9 a 300N force is applied horizontally to a 50kg crate pushing it 2m the force of friction between the crate and the floor is 200N the magnitude of the work done by the applied force is?A600JB200JC none of the above D400JE980J10 a 300N force is applied horizontally to a 50kg crate pushing it 2m the force of friction between the crate and the floor is 200N the magnitude of the work done by the frictional force is?A-600JB-400JC200JD980JE none of the above 11electrons with a speed of 1.0x10^7m/s strike the screen of a television set with what kinetic energy does a single electron hit the screen (mass of electron is 9.11x10^-31kg)A9.0x10^-17JB 4.5x10^-24JC9.0x10^-38JD9.0x10^-24JE4.6x10^-17J12A 1000kg car whose speed is 80km/h has kinetic energy of A 2.42x10^5JB2.47x10^3 JC2.52x10^2D8.0x10^5JE3.20x10^6J

A girl wants to slide down a 'frictionless' playground slide. If she starts at rest from X" and slides down to "?", which of the following slide shapes will give the girl the greatest possible speed upon reaching 'Y"? All the slides have the same vertical height. OAD O B) C OCA D) She gets to the bottom of all the slides with the same speed. O E B Question 14 (1 point) Using the five choices above, which slide (A. B. C, or D) will take the least time to descend? (If you think that they all will take the same time choose E. Al She gets to the bottom of all the slides at the same time. OBJ A