Question

9.
The velocity acquired by a body moving with
uniform acceleration is 30 ms in 2 seconds and
60 ms-in 4 seconds. The initial velocity is :​

Answer 1

t=2s , v=30m/s

t=4s , v=60m/s

a=dv/dt

=(60-30)/(4-2)

=30/2

=15m/s

Now,

v=u +at

u=v - at ........(calculate initial velocity)

u=30-15×2.......(after 2sec)

u=0m/s

Answer 2

Answer:

u=0

Explanation:

as given

making a new case

{where}. u=30ms

v=60ms

; so t=2sec

{ by solving for a}. a=15m/s^2. which is uniform

in case{1}===== v=30m/s

t=2sec

a=15m/s^2

u=?

{on solving for u we get }. u=0