Forces and Laws...

According to Newton's Third Law of Motion, action and reaction are equal and opposite. The resultant force is not zero because:

A driver first accelerates his car at a rate of $$\displaystyle 1.8{ m }/{ { s }^{ 2 } }$$ and then at a rate of $$\displaystyle 1.2{ m }/{ { s }^{ 2 } }$$. The ratio of the forces exerted by the engines respectively will be equal to

The rocket engine lifts a rocket from the earth, because hot gases:

A bullet of mass 0.01 kg is fired from a gun weighing 5.0 kg. If the initial speed of the bullet is 250 m/s, calculate the speed with which the gun recoils.

If the momentum of a body is doubled, the kinetic energy is

The mass of balloon and its contents is M. It is descending with an acceleration a. By how much the mass should be decreased, keeping the volume constant, so that the balloon starts ascending with the same acceleration? 

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

Two bodies of equal masses (M) moving with equal velocities (V) in opposite direction collide. Resultant velocity of the combination:

Mark the incorrect option:

Two tugboats are moving a barge. Tugboat A exerts a force of $$3000$$ newtons on the barge. Tugboat B exerts a force of $$5000$$ newtons in the same direction. What is the combined force on the barge?