Why is it advised to tie luggage with a rope on the roof of buses?

An object of mass $2\, kg$ is sliding with a constant velocity of $4\, m\, s^{-1}$ on a frictionless horizontal table. The force required to keep the object moving with the same velocity is (in $, N$)

How does the safety belt in a car help when a moving car applies brakes suddenly?

Inertia is that property of a body by virtue of which the body is

An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non-zero velocity? If yes,state the conditions that must be placed on the magnitude and direction of the velocity. If no,provide a reason.

$A$ javelin throw is marked foul if an athlete crosses over the line marked for throw. Explain why the athletes often fail to stop themselves before the line.