Question

A car travelling at 80 kmph can be stopped at a distance of 60 m by applying brakes. If the same car travels at 160 kmph and the same braking force is applied, the stopping distance is:

• A. \( 240 \) m
• B. \( 170 \) m
• C. \( 360 \) m
• D. \( 480 \) m

Hint:

Stopping distance varies with the square of the velocity when the braking force remains constant.

Answer 1

The Correct Option is A

Step 1: Use the Stopping Distance Formula Stopping distance \( d \) is given by: \[ d \propto v^2 \] Step 2: Calculate the New Stopping Distance Let \( d_1 = 60 \) m when \( v_1 = 80 \) kmph. For \( v_2 = 160 \) kmph: \[ \frac{d_2}{d_1} = \left(\frac{v_2}{v_1}\right)^2 \] \[ \frac{d_2}{60} = \left(\frac{160}{80}\right)^2 = 4 \] \[ d_2 = 4 \times 60 = 240 \text{ m} \]