Answer:
5.02s
Step-by-step explanation:
Given parameters:
Initial speed = 25m/s
Final speed = 30m/s
Distance = 138m
Unknown:
Time taken for the body to accelerate = ?
Solution:
We start by finding the acceleration of the body using the expression below;
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
30² = 25² + 2(a ) x 138
900 = 625 + 276a
900 - 625 = 276a
275 = 276a
a = 0.996m/s²
Now to find the time taken, use the expression below;
v = u + at
t is the unknown time;
30 = 25 + 0.996t
5 = 0.996t
t = 5.02s