Atennis ball with a speed of 27.7 m/s is
moving perpendicular to a wall. after striking
the wall, the ball rebounds in the opposite
direction with a speed of 19.7224 m/s.
if the ball is in contact with the wall for
0.0146 s, what is the average acceleration of
the ball while it is in contact with the wall?
take “toward the wall” to be the positive
direction.
answer in units of m/s
2
.

Two balls, each with a mass of 0.5 kg, collide on a pool table. is the law of conservation of momentum satisfied in the collision? explain why or why not

Astone is dropped from the upper observation deck of a tower, 250 m above the ground. (assume g = 9.8 m/s2.) (a) find the distance (in meters) of the stone above ground level at time t. h(t) = (b) how long does it take the stone to reach the ground? (round your answer to two decimal places.) s (c) with what velocity does it strike the ground? (round your answer to one decimal place.) m/s (d) if the stone is thrown downward with a speed of 2 m/s, how long does it take to reach the ground? (round your answer to two decimal places.) s

The gravitational force between pluto and charon is 3.61 × 1018 n. pluto has a mass of 1.3 × 1022 kg, which is only slightly greater than charon’s mass of 1.6 × 1021 kg. how far apart are pluto and charon? 2.0 × 107 m 2.4 × 1012 m 3.8 × 1014 m 5.8 × 1024 m