A0.43-kg soccer ball rolls toward an immoveable goalpost at a velocity of 6.8 m/s. assuming the collision between the soccer ball and goalpost is perfectly elastic, what is the velocity of the soccer ball after the collision?

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