Question

17) (a) Can any object have mechanical energy even if its momentum is zero. Explain
(b) Can any object have momentum even if its mechanical energy is zero? Explain

Answer 1

Dear Student ,
17.(a) Momentum is the product of mass and velocity of a body .Now for a particular body mass never be zero but velocity can be zero if a body is at rest .So if a body is at rest its momentum is zero but if it is in rest at a height it possesses gravitational potential energy hence mechanical energy .
(b) Here mathematically , K.E + P.E = 0
So , K.E = - P.E
since the velocity is zero so K.E = 0 .
But potential energy is equal to zero .
So the momentum hence is zero .since momentum = mass * velocity and here velocity = 0 .
Regards