Laws of Motion ...

Friction is a/an

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

A stone tied to a string is rotated in a vertical plane. If mass of the stone is $$m$$, the length of the string is $$r$$ and the linear speed of the stone is $$v$$,When the stone is at its lowest point, then the tension in the string will be :

In a circus, a motor cyclist moves in a spherical cage of radius $$5$$m. The minimum velocity with which he must cross the highest point without loosing contact is __________. (Take $$g=9.8m/s^2$$)

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

A molecule of mass $$m$$ of an ideal gas collides with the wall of the vessel with the velocity $$v$$ and returns back with the same velocity. The change in the linear momentum of the molecule will be:

An aircraft executes a horizontal loop with a speed of $$150$$ m/s with its wings banked at an angle of $$\displaystyle { 12 }^{ o }$$. The radius of the loop is $$\displaystyle \left( g=10{ m }/{ { s }^{ 2 } } \right) $$

A stone ties to a rope is rotated in a vertical circle with uniform speed. If the difference between the maximum and minimum tension in the rope is $$20\  N$$, mass of the stone in $$kg$$ is:
 ($$\displaystyle g=10{ ms }^{ -2 }$$)

The catcher prepares to receive a pitch from the pitcher. As the ball reaches and makes contact with his glove, the catcher pulls his hand backward. This action reduces the impact of the ball on the catcher's hand because:

In vertical circular motion, the ratio of kinetic energy to potential energy at the horizontal position is ____________.