Question

A toy car initially moving with a uniform velocity of 18 km/h comes to a stop in 2 s. Find the retardation of the car in S.I. units.

February 16, 2024

Answer

Initial velocity (u) = 18 km h^-1 or 5 m s^-1

Final velocity (v) = 0

Time (t) = 2 s

Acceleration (a) = $v-u\over t$

= $0-5\over 2$

= $-5\over 2$

= -2.5 m s ^-2

Hence, acceleration of the body is -2.5 m s ^-2. Negative sign shows that the velocity decreases with time, so retardation is 2.5 m s ^-2.

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