Question

a car moving at the speed of 72 km/h is brought to rest in 10 sec by applying brakes . find the magnitude of average retardation due to brakes and distance travelled by the car after applying brakes.

Answer 1

Answer:

$initial \: speed \: of \: car(u) = 72kmph = 20m/s \\ time \: = 10sec$

$final \: speed(v) = 0m / \: sec$

$retardation = \frac{u - v}{t}$

$= > \frac{20}{10} = 2m / {s}^{2}$

${v}^{2} - {u}^{2} = 2as$

$0 - {20}^{2} = 2 \times - 2 \times s$

$s = 100m$

Answer 2

Explanation:

s=100m

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