Question

a pebble thrown vertically upwards with an initial velocity 70m/s comes to stop in 7s
find the retardation.

pls explain step by step.​

Answer 1

initial velocity = 70 m/s

final velocity = 0 m/s

time = 7 s

acceleration = (v-u)/t

acceleration = (0-70)/7

acceleration = -70/7

acceleration = -10 m/s²

therefore, the retardation is 10 m/s² and the acceleration is -10 m/s²