Kinetic energy

9.Which of the following systems contain kinetic energy? (Select all that apply)

10.A bird in flight has kinetic energy.

11.Kinetic energy is proportional to the square of the speed of an object.

12.In the toy car experiment, when the car was going at slow speed it moved 250 cm, at medium speed 882 cm, and at fast speed 1450 cm. Which statement best explains the pattern?

13.A baseball and a wiffle ball are hit with the same force. The baseball goes farther because it has a larger mass. What does this demonstrate about kinetic energy?

14.Which of the following statements about kinetic energy are true? (Select all that apply)

15.Match each situation to the type of energy it primarily has (kinetic, potential, or both).

16.A student rolls a heavy glass marble and a light styrofoam ball of the same size down a ramp into a paper cup. The glass marble moves the cup 208 cm, while the styrofoam ball does not move the cup at all (0 cm). What is the most likely reason for this difference?

17.A race-car travelling at its maximum speed has kinetic energy.

18.Two identical cars are moving on a highway. Car A is travelling at 50 km/h and Car B is travelling at 100 km/h. How does the kinetic energy of Car B compare to that of Car A?

19.In the marble experiment, which of the following variables should be kept constant to ensure a fair test? (Select all that apply)

20.In the toy car experiment, the car moved 250 cm at slow speed, 882 cm at medium speed, and 1450 cm at fast speed. This data supports the claim that kinetic energy is directly proportional to speed.

21.In the toy car experiment, the car moved 250 cm at slow speed, 882 cm at medium speed, and 1450 cm at fast speed. If the speed of the car triples from slow to fast, what is the approximate ratio of the distances moved, and how does this compare to the expected ratio if kinetic energy is proportional to the square of the speed?

22.A stop street sign has kinetic energy.

23.A helicopter in flight has kinetic energy.

24.An apple hanging on a tree has kinetic energy.

25.Kinetic energy is proportional to the mass of the moving object.

26.In the toy car experiment, the car moved 250 cm at slow speed, 882 cm at medium speed, and 1450 cm at fast speed. If the speed doubles from slow to medium, the distance the car moves increases by approximately a factor of:

27.Complete the sentence:

28.In an experiment, a styrofoam marble (mass 0.2 g) moved a paper cup 0 cm, a plastic marble (9.5 g) moved it 107 cm, and a glass marble (20.4 g) moved it 208 cm. What is the distance the cup moved for the glass marble?

29.What is the energy of motion called?

30.In the marble experiment, a glass marble (mass 20.4 g) moved a paper cup 208 cm. A plastic marble (mass 9.5 g) moved the cup 107 cm. Approximately how many times greater is the kinetic energy of the glass marble compared to the plastic marble? (Give your answer to one decimal place.)

31.In the marble experiment, what property of the marble is changed to investigate its effect on kinetic energy?

32.Complete the sentence using the correct terms.

33.Complete the sentences below about energy changes for skydivers.

34.In the toy car experiment, the car moved 250 cm at slow speed, 882 cm at medium speed, and 1450 cm at fast speed. Explain how this data supports the claim that kinetic energy increases with speed.

35.In the marble experiment, a glass marble (mass 20.4 g) moved the cup 208 cm, while a styrofoam marble (mass 0.2 g) moved it 0 cm. Explain why the glass marble caused the cup to move much farther.

36.In an experiment, a styrofoam marble (mass 0.2 g) moved a paper cup 0 cm, a plastic marble (9.5 g) moved it 107 cm, and a glass marble (20.4 g) moved it 208 cm. What is the distance the cup moved for the glass marble?

37.In the marble experiment, a glass marble (mass 20.4 g) moved a paper cup 208 cm. A plastic marble (mass 9.5 g) moved the cup 107 cm. Approximately how many times greater is the kinetic energy of the glass marble compared to the plastic marble? (Give your answer to one decimal place.)

38.A high jumper sprints towards the bar, jumps, rises into the air, and lands on a soft mat. At the highest point of her jump, just above the bar, her upward speed is momentarily close to zero. What does this tell you about her energy at that instant?

39.As a skater speeds up, what happens to her kinetic energy (assuming her mass stays the same)?

40.Students dropped a glass marble (mass 18.5 g) into a cup of flour from a height of 50 cm. Its speed on impact was 3.1 m/s and its kinetic energy on impact was 88.9 g·m²/s². They repeated the drop from the same height using a glass marble with double the mass (37.0 g), and it hit the flour at the same speed, 3.1 m/s. How does the second marble's kinetic energy compare to the first marble's?

41.A student starts at rest on a bicycle and then rides faster and faster. Which graph best shows the relationship between her speed and her kinetic energy as she speeds up?

42.The graph shows the kinetic energy of three skaters (40 kg, 60 kg, and 80 kg) at the same ten positions on a half-pipe ramp, so at any one position all three skaters are moving at the same speed. Describe how the mass of a skater affected her kinetic energy. Use a quantitative example from one ramp position to support your answer.