Question

A B C D E 13. A box with a mass of 8.0 kg is lifted (without acceleration)

through a height of 2.0 m in order to place it upon the shelf of a closet. How many joules of work was required to lift the box to this position? a) 10, b) 16, c) 19.6, d) 157, e) none of the above.

A B C D E 14. To stretch a spring a distance of 0.20 m. 30 J of work is done. What is the value of the spring constant k of the spring? a) 6, b) 30, c) 150, d) 1500, e) none of the above.

A B C D E 15. At the low point in its swing, a pendulum bob with a mass of 0.2 kg has a velocity of 6 m/s. Ignoring air resistance, how many meters will the bob swing above the low point before reversing direction? a) 1.2, b) 1.84 m, c) 6, d) 12, e) none of the above.

A B C D E 16. A sled and rider with a combined mass of 60 kg are at the top of a hill a height of 15 m above the level ground below. The sled is given a push providing an initial kinetic energy at the top of the hill of 1600 J. After the push, what is the total mechanical energy of the sled and rider at the top of the hill? a) 900, b) 1600, c) 10.4 kJ, d) 24 kJ, e) none of the above.

A B C D E 17. A roller coaster car with a mass of 900 kg starts at rest from a point 20 m above the around. At point B, it is 12 m above the ground. If the initial kinetic energy was zero and the work done against friction between the starting point and point B is 30,000 J, what is the kinetic energy of the car at point B? a) 10.8 kJ, b) 20 kJ, c) 30 kJ, d) 40 kJ, e) none of the above.

Answer 1