The backward jerk felt when a gun is fired is an example of:

Which one of the following is an example of Second Class Lever?

When a stone tied to a string is whirled in a circle, the work done on it by the string:

Which of the following is a non-contact force ?

Assume 'A' does 500 J of work in 'x' minutes and 'B' does 1000 J of work in 20 minutes. If the power delivered by 'A' is P1​ and 'B' is P2​ and P1​=2P2​, then 'x', in minutes is:

A girl is swinging on a swing in sitting position. When the girl stands up, the period of the swing will :