A 0.25 kg ball is dropped from a 30 meter building. At the same time, a 2 kg ball is thrown downward with a 50 N force. Neglecting air resistance and after it is thrown, the ball will have an acceleration A. (a) equal to 8 times that of the dropped ball. B. (b) equal to 1/8 of that of the dropped ball. C. (c) equal to that of the dropped ball. D. (d) always larger than, but not always 8 times larger than, that of the dropped ball. E. (e) always smaller than, but not always 8 times smaller than, that of the dropped ball.

q20

1. A 100-g box slides across a frictionless horizontal plane and is accelerating at 15 m/s2. What is the opposing force needed to reduce the acceleration to 5 m/s2. Note that the question is asking for the opposing force to the original force, NOT the resultant force that results to 5 m/s2.

2. Imagine you are trying to move a very heavy box, and it does not move. Then, you get a friend to help you push and it begins to slide. Explain, in terms of the quantities discussed in this investigation (Fk, тах Hs,Fk9 Hk) what is happening to the box in these two cases.

35. A small block slides along the inside of a frictionless vertical circular track. At the high point of the motion the block's acceleration has magnitude 2g. What is the magnitude of the block's acceleration at the low point? a) 6g ☐ b) 5g c) 4g d) 3g e) 2g (numbers 36-37) An object's position versus time graph is shown.