Question

A ball is gently dropped from a height of
20 m. If its velocity increases uniformly at
the rate of 10 ms?, with what velocity will
it strike the ground? After what time will it
strike the ground?​

Answer 1

Answer:

Explanation:

initial velocity, u = 0 (dropped gently); Acceleration, a = 10 m/s2

Height, s = 20 m; Final velocity, v =? And Time taken, t =?

 

Use third equation of motion:

begin math size 12px style straight v squared equals straight u squared plus 2 as

rightwards arrow straight v squared equals 0 plus 2 cross times 10 cross times 20

rightwards arrow straight v squared equals 400

rightwards arrow straight v equals 20 space straight m divided by straight s

Using space the space second space equation space of space motion comma space we space get

straight s equals ut plus 1 half at squared

rightwards arrow 20 equals 0 cross times straight t plus 1 half cross times 10 cross times straight t squared

rightwards arrow straight t squared equals 4

rightwards arrow straight t equals 2 space straight s end style

Answer 2

Answer:

use third equation of motion.