Question

A bus at rest accelerates uniformly to a velocity of 54km/hr in 20s.How much distance is travelled by the bus in 20s

Answer 1

Explanation:

Given -

u = 0

v = 54 km/h

=54×5/18

=15m/s

t = 20sec

s =?

a=?

v=u + at

15=0+a×20

a=15/20

a = 0.75m / s ^2

s=ut + 1 / 2 at ^2

s = 0×20+1/2×0.75×20×20

s = 150m

Answer 2

Answer:

Given,

u = 0 m/s

v = 54 km/hr

= 54 x 5/18

= 3 x 5

= 15 m/s

t = 20 sec

Using 1st equation of motion,

v = u + at

therefore, a = v - u/t

a = 15 - 0/20

a= 15/20

a= 3/4

a = 0.75 m/s^2

To find s (distance),

using 2nd equation of motion

i.e., s = ut + 1/2 at^2

s = 0 x 20 + 1/2 x 0.75 x 20 x 20

s = 0 + 1/2 x 75/100 x 20 x 20

s = 1/2 x 75 x 2 x 2

s = 150 m

Ans - The distance travelled is 150m.

Hope it helped u.