Aball of moist clay falls 19.3 m to the ground. it is in contact with the ground for 21.0 ms before stopping. (a) what is the average acceleration of the ball during the time it is in contact with the ground? (treat the ball as a particle.) (b) is the average acceleration up or down?

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.