Question

If a vhhicle starting from rest gains a velocity of 54 km per hr in 30 seconds what is its acceleration? How far travel in 60 second.

Answer 1

Initial velocity (u) = 0 m/s

Final velocity = 54 km/h = 15 m/s

Let the acceleration be a.

Time taken to reach the 15 m/s (t) = 30 seconds

Using the first equation of motion:

v = u + at

$a = \frac{v-u}{t}$

$a = \frac{15 - 0}{30}$

a = 0.5 m/s^2

Let the distance covered be s.

Using the seconds equation of motion:

$s = ut + \frac{1}{2}a t^2$

$s = 0 + \frac{1}{2}\times 0.5 \times 30 \times 30$

s = 450 meters