Question

From rescue step on the gas of your car providing a force F for for second speeding it up to a final speed of V if the applied force were only 1/2 F how long would it have to be applied to reach the same final speed

Answer 1

Acceleration = force /mass

Since mass is constant,

Therefore acceleration is directly proportional to the force.

Therefore in second case when applied force is F/2 , then acceleration will also be a/2 in this case.

Also , using equation of motion, V = u + at

Which means final speed (V) is directly proportional to the product of acceleration (a) and time (t).

Since the acceleration in case 2 is a/2 , therefore the time taken to reach the same speed V will be 2t in this case.

Finally, in short we can say that time taken to reach the same speed when force is reduced to half(F/2) will be twice the time taken when the force applied was F.

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