(a)
Consider a body has initial velocity (u) . Suppose it is subjected to a uniform acceleration (a) such that after time (t) its final velocity becomes (v). Now, from the definition of acceleration we know that:
The above expression can also be written as,
On further simplification, we get the 1st equation of motion,
v = u + at
Where,
(a) - Acceleration
(v) - Final velocity
(u) - Initial velocity
(t) - Time taken
The equation v = u + at is called the first equation of motion and is used to calculate the velocity 'v' acquired by a body in time 't'.
(b) We have to find the value of uniform acceleration. So,
Initial velocity
Final velocity (v) = 0 m/s
Time taken(t) = 8 s
So acceleration,
Put the values in the above equation to get the value of acceleration