Question

a car travelling at 36 km/hr speeds upto 42 km/hr in 5 seconds. What is the acceleration if the same car stops in 20 seconds. What is the retardation?

Answer 1

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Answer 2

v = 42kmph = 42 × 5/18m/s = 11.6m/s

u = 36kmph = 36 × 5/18m/s = 10m/s

t = 5s

a = (v - u) / t

= (11.6 - 10) / 5

$a = 0.32ms {}^{ - 2}$

If car stops in 20s then V =0 and u = 42m/s

a = (v - u) / t

= (0 - 42) / 20

$retardation = 1.2ms {}^{ - 2}$

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