Question

an object starting from rest moves with constant acceleration of 4m/s^2 after 8 second its speed is

Answer 1

initial velocity will be 0m/s as it starts from rest.
final velocity we have to find .
v=u +at
v=0 + 4× 8 ( acc. and time is given)
v= 32 m/s^

Answer 2

hello your answer ..

object is at rest means initial velocity of the object should be (u) = 0 m/s
acceleration of the object (a) = 4 m/s^2
time (t) = 8 seconds .

we know that,

v=u+at
v=0+4(8)
$\bold{\italic{\boxed{\boxed{v= 32 m/s}}}}$