Question

A pebble is thrown vertically upwards with an initial velocity 5m/s comes to a stop in 5 s find its acceleration

Answer 1

initial /time

5/5

1

is the accleration

Answer 2

since the pebble is thrown vertically upward therefore *final velocity* will be 0
final velocity (v)=0
initial velcity (u)= 5m/s
time taken (t)= 5s
formula for acceleration is
$\frac{(v - u)}{t}$
(0–5)/5
=–5/5
= –1 m/s²
acceleration = –1 m/s² or retardation (since velocity decreases )= 1m/s²