Define is work.  

Define energy.  

What is the scalar product ?  

Explain the distributive law.  

Define work.  

Define kinetic energy.  

Work done by a body against friction always results in a loss of its kinetic/potential energy.  

In an elastic collision of two bodies, the momentum and energy of each body is conserved.  

Is the total linear momentum conserved during the short time of an elastic collision of two balls?  

During inelastic collision between two bodies, which of the Kinetic energy.