Question

Which of the following statements are true about a mass rotating around a string? Select all that apply.

Group of answer choices

A. If you cut the string as the ball is in motion, the ball will continue to move in uniform circular motion due to the centripetal force.

b. The acceleration and velocity vectors on the mass will always be perpendicular to each other.

c. Since the linear speed of the rotating mass is constant, the kinetic energy of the mass is also constant.

d. The acceleration and centripetal force vectors will always be directed inward, towards the center of the arc.

Answer 1

Only (C) and (D) are true

a = (v2 - v1) / t since a and v are vector quantities they have the same direction

Also KE = 1/2 M v^2 describes the linear KE of an object moving with a speed of v

Also KE = F * S where S is the displacement - the radius vector is a constant for an object moving in a circle and the centripetal force provides no change in KE