Whether work done is positive, negative, or zero.

Question

m C A block of mass m slides down a ramp of height hand collides with an identical block that is initially at rest. The two blocks stick together and travel around a loop of radius R without losing contact with the track. Point A is at the top of the loop, point B is at the end of a horizon- tal diameter, and point C is at the bottom of the loop, as shown in the figure above. Assume that friction between the track and blocks is negligible. (a) The dots below represent the two connected blocks at points A, B, and C. Draw free-body dia- grams showing and labeling the forces (not com ponents) exerted on the blocks at each position. Draw the relative lengths of all vectors to reflect the relative magnitude of the forces. Point A Point B Point C (b) For each of the following, derive an expression in terms of m, h, R, and fundamental constants. i. The speed of moving block at the bottom of the ramp, just before it contacts the stationary block ii. The speed of the two blocks immediately…

Answer 1

Question

Chapter 9, Problem 34PQ

(a)

To determine

Whether work done is positive, negative, or zero.

(b)

To determine

Whether work done is positive, negative, or zero, when a man moves a child in a stroller across a frictionless floor so that the man and child glide together at a constant speed.

(c)

To determine

Whether work done is positive, negative, or zero, when a man prevents a child in a stroller from accelerating as it travels downhill.

(d)

To determine

Whether work done is positive, negative, or zero, when a man pushes the Great Wall of China, yet it remains motionless.

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