CHAPTER S REVIEw 87 THINK AND RANK (ANALYSIS) 31. A van exerts a force on traile
ID: 1773970 • Letter: C
Question
CHAPTER S REVIEw 87 THINK AND RANK (ANALYSIS) 31. A van exerts a force on trailers of different masses m Compared with the force exerted on each trailer, rank the magnitudes of the forces cach trailer exerts on the van. (Or are all pairs of forces equal in magnitude?) a-The accelerations of the boxes m-1000 kg v- 20 m/s m-1500 kg v 20 m/s b. The tensions in the ropes connected to the single 33. Three identical pucks, A. B, and C, are sliding across ice a. Rank the pucks by the force needed to keep them b. Rank the pucks by the force needed to stop them in boxes to the right in B and in C at the given speeds. The forces of air and ice friction are m-1800 kg v-15m/s moving, from greatest to least 32. Each of these boxes is pulled by the same force Fto the left. All boxes have the same mass and slide on a friction- free surface. Rank the following from greatest to least the same time interval, from greatest to least 2 m/s 6 mis THINK AND EXPLAIN (SYNTHESIS) 34. For each of the following interactions, identify action 40. What physics is involved for a passenger feeling pushed 41. If you drop a rubber ball on the floor, it bounces back 42. Within a book on a table, there are billions of forces pushing and reaction forces: (a) A hammer hits a nail. (b) Earth gravity pulls down on a book. (e) A helicopter blade pushes air downward. backward into the seat of an airplane when it accelerates along the runway during takeoff? 35. The photo shows Steve Hewitt and daughter Gretchen. up. What force acts on the ball to provide the bounce is Gretchen touching her dad, or is her dad touching her? and pulling on all the molecules, Why is ir that chese forces never by chance add up to a net force in one direction, caus- ing the book to accelerate "spontancously" across the table 43. If you exert a horizoncal force of 200 N to slide a crate across a factory floor at constant velocity, how much friction is exerted by the floor on the crate? Is the force of friction equal and oppositely directed to your 200-N push? If the force of friction isn't the reaction force to your push, what is 44. When the athlete holds the barbell overhead, the reaction force is the weight of the barbell on his hand. How does this force vary for the case in which the barbell is accelerated upward? Downward? 36. When you rub your hands together, can you push harder on one hand than the other? 37. You hold an apple over your head. (a) Identify all the forces acting on the apple and their reaction forces. (b) When you drop the apple, idencify all he forces acting on it as i falls and the corresponding reaction forces. Ignore air drag. 5. Consider the two forces acting on the person who stands still-namely, the downward pull of gravity and the upward support of the floor. Are these forces equal and opposite? Do they form an action- reaction pair? Why or why not 38. Identify the action-reaction pairs of forces for the follow ing situations: (a) You step off a curb. (b) You pat your tutor on the back. (c) A wave hits a rocky shore. 39. Consider a baseball player batting a ball. Identify the 46. Why can you exert greater force on the ng hit and pedals of a bicycle if you pull up on the handlebars? (b) while the ball is in flightExplanation / Answer
Q31.
All are the same because all the velocities are constant
Q32.
a. ABC
b. BC
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