The equation of motion of a car is s = t^2 - | vedclass

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(D) Given the equation of motion: $s = t^2 - 2t$ $(i)$The velocity $v$ is the rate of change of displacement with respect to time,so $v = \frac{ds}{dt

Vedclass · Accepted Answer

$8$

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(D) Given the equation of motion: $s = t^2 - 2t$ $(i)$The velocity $v$ is the rate of change of displacement with respect to time,so $v = \frac{ds}{dt} = 2t - 2$ $(ii)$Given that the distance travelled $s = 15 \, km$,we substitute this into equation $(i)$:$15 = t^2 - 2t$$t^2 - 2t - 15 = 0$Factoring the quadratic equation:$(t - 5)(t + 3) = 0$Since time $t$ cannot be negative,we have $t = 5 \, hours$.Now,substitute $t = 5$ into equation $(ii)$ to find the velocity:$v = 2(5) - 2 = 10 - 2 = 8 \, km/h$.Therefore,the velocity of the car is $8 \, km/h$.

The equation of motion of a car is $s = t^2 - 2t$,where $t$ is measured in hours and $s$ in kilometers. When the distance travelled by the car is $15 \, km$,the velocity of the car is ......... $km/h$.

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