Question

Two cars of unequal masses use similar tyres. If they are moving at the same initial speed, the minimum stopping distance

• A. $\text{is smaller for the heavier car}$
• B. $\text{is smaller for the lighter car}$
• C. $\text{is same for both cars}$
• D. $\text{depends on the volume of the car}$

Answer 1

The correct option is C $\text{is same for both cars}$

During slipping, the force of friction on a car $=\mu mg$ (where, $m$ is the mass of the car and $\mu$ is the coefficient of kinetic friction).
The deceleration of the car is
$a=\frac{Force}{mass}=\frac{\mu mg}{m}=\mu g$.
This expression for deceleration is independent of $m$ i.e. mass of the car.
So, the minimum stopping distance is the same for both cars.