Question

3. Why is it advised to tie any luggage kept on the roof of a bus
with a rope?
​

Answer 1

Answer:

The luggage is tied to the bus so that it won't fall when applied brake due to inertia of its motion prior to application of brakes.

Answer 2

Answer:

When some luggage is placed on the roof of a bus which is initially at rest, the acceleration of the bus in the forward direction will exert a force (in the backward direction) on the luggage. In a similar manner, when a bus which is initially in a state of motion suddenly comes to rest due to the application of brakes, a force (in the forward direction) is exerted on the luggage.

Depending on the mass of the luggage and the magnitude of the force, the luggage may fall off the bus due to inertia. Tying up the luggage will secure its position and prevent it from falling off the bus.