2011 Midterm Review

1. 2011 Midterm Review Physics Ms. Allison

2. An airplane flying into a head wind loses ground speed, and an airplane flying with the wind gains ground speed. If an airplane flies at right angles to the wind, then ground speed is

3. Answer • An airplane flying into a head wind loses ground speed, and an airplane flying with the wind gains ground speed. If an airplane flies at right angles to the wind, then ground speed is

4. A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always

5. Answer A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always

6. An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the

7. Answer An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the

8. A car driving straight down the street has

9. Answer A car driving straight down the street has

10. What do we know about energy based on the conservation of energy?

11. Answer What do we know about energy based on the conservation of energy? According to the conservation of energy, we know the energy is neither loss or created only transferred from one form to another.

12. The center of gravity of a human body is located at a point

13. Answer The center of gravity of a human body is located at a point

14. Which has greater tangential speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?

15. Answer Which has greater tangential speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?

16. Which has greater rotational speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?

17. Answer Which has greater rotational speed, a horse near the outside rail of a merry-go-round or a horse near the inside rail?

18. A scalar is a quantity that has

19. Answer A scalar is a quantity that has

20. Which rolls to the bottom of a hill sooner, a car tire alone or the same tire mounted on a rim?

21. Answer Which rolls to the bottom of a hill sooner, a car tire alone or the same tire mounted on a rim?

22. What has more influence on kinetic energy; mass or velocity?

23. Answer What has more influence on kinetic energy; mass or velocity? Velocity because it is squared in the kinetic energy equation

24. What is the relationship between kinetic energy and conservation of energy?

25. Answer • What is the relationship between kinetic energy and conservation of energy? Kinetic energy is the energy of motion. When one moving object hits another, the energy is transferred between the objects since energy cannot be creates nor destroyed according the law of the conservation of energy.

26. How fast does Kenny run the 100 m dash if he crosses the finish line in 10 s?

27. Answer Known d = 100m t = 10s Unknown v Equation v = d/t Solve v = d/t = 100 m 10s = 100 m/s

28. About how tall is a tree, if it takes 1.2s for an apple to fall to the ground from the very top branch?

29. Answer Known t =1.2s g = 10m/s2 vo = 0 Unknown d Equation d = vot + ½ gt2 Solve d = vot + ½ gt2 = (0)(1.2s) + ½(10m/s2)(1.2s)2 = ½(10m/s2)(1.2s)2 = ½(10m/s2)(1.44s2) = (5m/s2) (1.44s2) = 7.2 m

30. Michael is 75kg and runs up the a 5 m high hill in 25s. What is his power input?

31. Answer Known m = 75kg d = 5m t = 25s Unknown Power Equation Power = W/t Solve Power = W/t = Fd/t (remember Force times distance is work) = mgd/t (remember Force is mass times gravity) = (75kg)(10m/s2)(5m) 25s = 3750 kg m2/s2 25s = 150 W