Unit 1-3 Review

1. Unit 1-3 Review

2. Ft = 50N Mass = 4 kg, acceleration = 5m/s2 → Find the weight - Fg (N)

3. Ft = 50N Mass = 4 kg, acceleration = 5 m/s2 Fg = 40 N What is the normal Force?

4. Ft = 50N Mass = 4 kg, acceleration = 5 m/s2 Fg = 40 N What is the net Force?

5. Ft = 50N Mass = 4 kg, acceleration = 5 m/s2 Fg = 40 N, Fnet = 20 N What is the frictional Force?

6. Ft = 50N Mass = 4 kg, acceleration = 5 m/s2 Fg = 40 N, Fnet = 20 N, Ff = 30N What is µ?

7. 2nd and 3rd Law Cannon and Cannonball F = F Ma = mA

8. Velocity is to speed as displacement is to (A) acceleration (B) momentum (C) time (D) distance

9. Convert 50.1 km to m

10. An airplane travels at an average speed of 400 mile/hour. How many hours will it take the plane to fly 1200 miles?

11. A car accelerates from a position of rest to 50 m/s in 20 seconds. Determine the rate of acceleration in m/s2

12. A car accelerates from a position of rest to 50 m/s in 20 seconds. Determine the rate of acceleration in 2.5 m/s2 Calculate the speed (m/s) of the car at the end of the first 6 seconds.

13. The diagram shows a resultant vector, R. Which diagram best represents a pair of component vectors, A and B, that would combine to form resultant vector R?

14. A person is standing on a bathroom scale in an elevator car. If the scale reads a value greater than the weight of the person at rest, the elevator car could be moving (A) downward at constant speed (B) upward at constant speed (C) downward at increasing speed (D) upward at increasing speed

15. The diagram represents the path of an object after it was thrown. What happens to the object’s acceleration as it travels from A to B? (A) It decreases. (B) It increases. (C) It remains the same.

16. A 0.2-kg red ball is thrown horizontally at a speed of 4 m/s from a height of 3 meters. A 0.4-kg green ball is thrown horizontally from the same height at a speed of 8 m/s. Compared to the time it takes the red ball to reach the ground, the time it takes the green ball to reach the ground is (A) one-half as great (B) the same (C) twice as great (D) four times as great

17. The acceleration due to gravity on the surface of planet X is 19.6 m/s2. If an object on the surface of this planet weighs 980 Newtons, the mass of the object in kilograms is

18. The acceleration due to gravity on the surface of planet X is 19.6 m/s2. How far will an object fall in 3 seconds?

19. A basketball player jumped straight up to grab a rebound. If she was in the air for 0.80 second, how long did it take to reach the top of her jump?

20. A basketball player jumped straight up to grab a rebound. If she was in the air for 0.80 second, how high did she jump?

21. The force required to start an object sliding across a uniform horizontal surface is larger than the force required to keep the object sliding at a constant velocity. The magnitudes of the required forces are different in these situations because the force of kinetic friction (A) is greater than the force of static friction (B) is less than the force of static friction (C) increases as the speed of the object relative to the surface increases (D) decreases as the speed of the object relative to the surface increases

22. A man is pushing a baby stroller. Compared to the magnitude of the force exerted on the stroller by the man, the magnitude of the force exerted on the man by the stroller is (A) zero (B) smaller, but greater than zero (C) larger (D) the same

23. A constant unbalanced force is applied to an object for a period of time. Which graph best represents the acceleration of the object as a function of elapsed time?

24. The diameter of a United States penny is closest to (A) 100 m (B) 10–1 m (C) 10–2 m (D) 10–3 m

25. During a 5.0-second interval, an object’s velocity changes from 25 meters per second east to 15 meters per second east. Determine the magnitude of the object’s acceleration in m/s2.

26. A projectile has an initial horizontal velocity of 15 meters per second and an initial vertical velocity of 25 m/s. Determine the projectile’s horizontal displacement (in m) if the total time of flight is 5.0 seconds.

27. A projectile has an initial horizontal velocity of 15 meters per second and an initial vertical velocity of 25 m/s. Determine the maximum height of the projectile (in m) if the total time of flight is 5.0 seconds.

28. A net force of 25 Newtons is applied horizontally to a 10-kilogram block resting on a table. What is the magnitude of the acceleration of the block? (A) 0.0 m/s2 (B) 0.40 m/s2 (C) 0.26 m/s2 (D) 2.5 m/s2

29. The speed of a car is increased uniformly from 20 meters per second to 30 meters per second in 4.0 seconds. The magnitude of the car’s average acceleration in this 4.0-second interval is (A) 0.40 m/s2 (B) 10 m/s2 (C) 2.5 m/s2 (D) 13 m/s2

30. A box is at rest on an inclined plane. Which vector best represents the direction of the normal force acting on the box? (A) A (B) B (C) C (D) D

31. If the magnitude of the gravitational force of Earth on the Moon is F, the magnitude of the gravitational force of the Moon on Earth is (A) smaller than F (B) larger than F (C) equal to F

32. Which term represents a scalar quantity? (A) distance (B) force (C) displacement (D) weight

33. An apple weighing 1 Newton on the surface of Earth has a mass of approximately (A) 1×10–1 kg (B) 1×100 kg (C) 1×101 kg (D) 1×102 kg

34. In which situation is the net force on the object equal to zero (mechanical equilibrium)? (A) a satellite moving at constant speed around Earth in a circular orbit (B) an automobile braking to a stop (C) a bicycle moving at constant speed on a straight, level road (D) a pitched baseball being hit by a bat

35. A 10.0-kilogram mass are held at rest on a frictionless 30.0° incline by force F. What is the approximate magnitude of force F? (A) 9.81 N (B) 85.0 N (C) 49.1 N (D) 98.1 N

36. The graph shows the velocity of a race car moving along a straight line as a function of time. What is the magnitude of the displacement of the car from t = 2.0 seconds to t = 4.0 seconds? (A) 20 m (B) 40 m (C) 60 m (D) 80 m 36

37. Which vector diagram represents the greatest magnitude of displacement for an object?

38. A child is flying a kite, K. A student at point B, located 100. meters away from point A (directly underneath the kite), measures the angle of elevation of the kite from the ground as 30°. Determine the height, AK, in meters of the kite.

39. A child is flying a kite, K. A student at point B, located 100. meters away from point A (directly underneath the kite), measures the angle of elevation of the kite from the ground as 30°. A small lead sphere is dropped from the kite. Calculate the amount of time required for the sphere to fall to the ground.

40. A car traveling on a straight road at 15.0 m/s accelerates uniformly to a speed of 21.0 m/s in 12.0 seconds. What is the acceleration in m/s2?

41. A golf ball is hit with an initial velocity of 15 m/s at an angle of 35 degrees above the horizontal. What is the vertical component of the golf ball’s initial velocity in m/s?

42. A golf ball is hit with an initial velocity of 15 meters per second at an angle of 35 degrees above the horizontal. What is the horizontal component of the golf ball’s initial velocity?

43. Goofy the clown is working in Lost Wages & wants to jump off the top of the Bellagio which is 155-m tall and land in the pool which is 21-m away from the base of the hotel. How many seconds will Goofy be falling?

44. Goofy the clown is working in Lost Wages & wants to jump off the top of the Bellagio which is 155-m tall and land in the pool which is 21-m away from the base of the hotel. t = 5.6 s How fast will Goofy need to run (m/s) so he does not hit the concrete between the hotel and the pool?

45. For his next stunt, Goofy wants to be shot out of a cannon and land in a barrel of water. Goofy will leave the cannon at 100 m/s at an angle of 45o. What is Goofy’s vertical velocity as he leaves the cannon?

46. For his next stunt, Goofy wants to be shot out of a cannon and land in a barrel of water. Goofy will leave the cannon at 100 m/s at an angle of 45o. vv = 70.7 m/s How many seconds will it take Goofy’s to reach his maximum height?

47. For his next stunt, Goofy wants to be shot out of a cannon and land in a barrel of water. Goofy will leave the cannon at 100 m/s at an angle of 45o. vv = 70.7 m/s, t = 7.1 s What is the minimum height for the tent so Goofy does not scrape the top?

48. For his next stunt, Goofy wants to be shot out of a cannon and land in a barrel of water. Goofy will leave the cannon at 100 m/s at an angle of 45o. vv = 70.7 m/s, t = 7.1 s, y = 250 m What is Goofy’s horizontal velocity (m/s) as he leaves the cannon?

49. For his next stunt, Goofy wants to be shot out of a cannon and land in a barrel of water. Goofy will leave the cannon at 100 m/s at an angle of 45o. vv = 70.7 m/s, t = 7.1 s, y = 250 m vH = 70.7 m/s How far from the cannon does the barrel of water need to be placed?

50. In a plane that goes 310 m/s the pilot wants to fly directly north when the wind is blowing at 155 m/s from the east. (a) In what direction must he head the plane?