Question

Which statement are not correct-
[a] A body can have momentum without kinetic energy.
[b] The relative velocity of the two particles in head on collision is unchanged both in magnitude and direction.
[c] P.E of an object can have a negative value
[d] K.E. of an object can have a negative value

• A. a, c, d
• B. a, b, c
• C. a, b, d
• D. a, b, c, d

Answer 1

Answer: (C)

a, b, d

a. if body has momentum then i has velocity implying it has KE.

b. a simple contradiction is after the collision if two approaching balls go apart then the direction of velocities just reversed.

d. KE = 0.5mv^2 , neither v^2 nor m can be negative so KE is always positive.