Question

5) When brakes are applied to a bus, the
retardation produced is 25m/s2
and the bus takes 20 sec to stop.
Calculate the initial velocity of the
bus.
ANA​

Answer 1

V=u-at

0=u-0.25*20

-u=-5

so u=5m/s

s=ut-1/2*a*t*t=5*20-1/2*0.25*20*20=100-50=50metres

Answer 2

Answer:

Explanation:

Solution,

Here, we have

Final velocity, v = 0 m/s (As brakes applied)

Retardation, a = - 25 m/s²

Time taken, t = 20 seconds

To Find,

Initial velocity, u = ?

According to the 1st equation of motion,

We know that

v = u + at

So, putting all the values, we get

v = u + at

⇒ 0 = u + (- 25) × 20

⇒ - u = - 500

⇒ u = 500 m/s

Hence, the initial velocity of bus is 500 m/s.