Question

A particle moves in a straight line with constant acceleration it changes its velocity from 10 metre per second to the - 120 metres per second into minus 11 passing through a distance 135 metre per second the value of t is​

Answer 1

Correct question :

A particle moves in a straight line with constant acceleration it changes its velocity from 10 ms^-1 to 20 ms^-1 while passing through a distance 135 metre per second the value of t is

Solution :

initial velocity u = 10ms^-1

final velocity v = 20 ms^-1

distance s = 135 m

let acceleration = a

using formula v² = u² + 2as

a = v² - u²/2s

= (20)² - (10)²/2 x 135

= 400 - 100/2 x 135

= 300/2 x 135

= 150/135

= 10/9 ms^-2

now using the relation v = u + at

t = v - u/a

= 20 - 10/10/9

= 10/10 x 9 sec

t = 9 sec