Question

A bus can be stopped by applying a retarding force F when it is moving with a speed v on a level road. The distance covered by it before coming to rest is s. If the load of the bus increases by 50 % because of passengers, for the same speed and same retarding force, the distance covered by the bus to come to rest shall be

• A. 1.5 s
• B. 2 s
• C. 1 s
• D. 2.5 s

Answer 1

Answer: (A)

1.5 s

Answer 2

Retarding force (F) × distance covered (x) = Kinetic energy

$\left( \frac { 1 } { 2 } m v ^ { 2 } \right)$

If v and F are constants then x ∝ m

∴ ⇒ x₂ = 1.5 s.