Question

(4. A bus is moving at 25 m/s when the driver steps on the brakes and brings the bus to a stop in

Answer 1

Answer:

(a)  the average acceleration of the bus while braking is 8.333 m/s

(b) if the bus took twice as long to stop, the acceleration will be half of the value obtained in part a.  [¹/₂ (8.333 m/s) = 4.16 s]

Explanation:

Given;

initial velocity of the bus, v = 25 m/s

time of the motion, t = 3 s

(a)  the average acceleration of the bus while braking

a = dv/dt

where;

a is the bus acceleration

dv is change in velocity

dt is change in time

a = 25 / 3

a = 8.333 m/s

(b) If the bus took twice as long to stop, the duration = 2 x 3s

a = 25 / (2 x 3s)

a = ¹/₂ x (25 / 3)

a = ¹/₂ (8.333 m/s) = 4.16 s

Thus, if the bus took twice as long to stop, the acceleration will be half of the value obtained in part a.