1. An apple hanging from a limb has potential energy because of its height. If it falls, what becomes of this energy just before it hits the ground? a. its total energy goes to zero b. its P.E. is transformed into kinetic energy c. its energy is transformed into the thermal energy of the apple and the ground d. its P.E. increases and just before it hits the ground it is doubled 2. An energy bar contains 105 kilocalories. How much work is the equivalent of this energy bar? a. 25.06 KJoules b. 439.95 kJoules c. 10.5 kJoules d. 0.14 Joules

16. A person runs at a speed of 4.50 m/s uses 760 Jof energy. Solve for the person's mass. (ans: 75.1 kg) 17. A car with a mass of 2200 kg has a kinetic energy of 990 k). Solve for the speed of the car. (ans: 30 m/s)

Timmy (m=50kg) is at the top of a 7m tall hill. a. What type of energy does he have at the top of the hill? b. What is his potential energy? c. What type of energy does he have at the bottom of the hill? d. What is his speed at the bottom of the hill, after he slides down it? e. The hill has a river at the bottom, that causes two things. First is a vertical drop of 2m, second is a horizontal gap. What distance is the gap if Timmy makes the jump? Here you may also assume that at the bottom of the hill Timmy flies horizontally off.

You take a 13kg bag of lead pellets and drop it from 2m above the ground.a. How much gravitational potential energy does the bag have when held 2m above the ground?b. The bag is dropped. Just before it hits the ground, how much kinetic energy does it have?c. How fast is the bag moving just before it hits the ground?d. When it hits the ground, the kinetic energy will be transformed mostly into thermal energy. If 40%of this energy goes into the lead pellets as heat, what will be the increase in temperature of thelead? Assume led has a specific heat capacity of 160J/kg·K.

2. A ball is dropped from the top of a building. You choose the top of the building as a reference point while your friend chooses the bottom as the reference point. Explain whether the energy calculated using the two different reference points are same or different. a. The ball PE at any point b. Change in PE as a result of the fall KE at any point C.

11. How much work does Amanda's car experience compared to Bertha's? Amanda and Bertha are in a car race. Their cars have the same mass. At one point in the race, they both change their speeds by 10 m/s in 2 seconds. Ignore air friction. 2s later 2s later 10 m/s 20 m/s 20 m/s 30 m/s Amanda Bertha a. Amanda's car experiences less work b. Amanda's and Bertha's car experience the same amount of work c. Amanda's car experiences more work. O d. Only Rihanna would know. (Work Work Work Work Work...) 96 alt

10. Jared and Clay are climbing the stairs. Jared gets tired and stops halfway to the fourth floor. Clay makes it to the fourth floor v.. a problem. If Jared is twice as heavy as Clay, who has more potential energy? Explain.

2. Consider the concepts of kinetic energy (KE) and gravitational potential energy (GPE) as you complete these questions. A ball is held 1.4 meters above the floor. Use the terms KE of GPE as your answers. A. When the ball is held motionless above the floor, the ball possesses only B. If the ball is dropped, its energy decreases as it falls. C. If the ball is dropped, its energy increases as it falls. D. In fact, in the absence of air resistance, the amount of impact with the floor. energy. energy when the ball is held motionless above the floor equals the amount of energy at

Which of the following statements are TRUE? A. Energy is a vector physical quantity. B. Energy is always required to do work. C. Totol mechanical energy can never be zero. D. When law of conservation of mechanical energy is invoked, there can never be a waste energy in an ideal system. E. When law of conservation of mechanical energy is invoked, there can never be a waste energy in a real-world system. F. Kinetic energy can be negative. G. Potential energy can be negative. H. Work is equivalent to the negative change in kinetic energy. I. Work is equivalent to the negative change in potential energy. J. In a conservative system where only gravitational force acts, the total mechanical energy is constant at every point of the motion. K. In a non-conservative system where certain external forces may act, the total mechanical energy is not constant at every point of the motion. L The entire universe may be considered as a closed system where the total energy is constant. chnices O B. D.…

4. A 6.00 Kg iron ball moves at 2.75 m/s. How fast must a 2.65 g steal ball move so that the two balls have the same kinetic energy?