When brakes are applied to a bus, retardation produced is 25 cm s-2 and the bus takes 20 s to stop.
Calculate
(i) The initial velocity of the bus
(ii) The distance travelled by the bus during this time.
Final velocity v = 0
Acceleration = -25 cm/s2 or -0.25 m/s2
Time taken t = 20 s
(i) Let 'u' be the initial velocity.
Using the first equation of motion,
v = u + at
We get,
u = v - at
u = 0 - (-0.25)(20) = 5 m/s-1
(ii) Let 's' be the distance travelled.
Using the third equation of motion,
v2 - u2 = 2as
We get,
(0) 2 - (5)2 = 2 (-0.25) (s)
s = (25/0.5) = 50 m.
Concept: Distance and Displacement
Is there an error in this question or solution?