Question

An object A has half the mass and twice the velocity of object B. How are the kinetic energies of A and B related?

A. The kinetic energy of A is the same as that of B.
B. The kinetic energy of B is twice that of A.
C. The kinetic energy of A is twice that of B.
D. The kinetic energy of B is 4 times that of A.

Answer 1

B = (1/2) M V^2

A = (1/2) (1/2 * M) (2V^2)

plug in an example like M = 2 V = 4

B = (1/2) (2) (16) = 16J
A = (1/2) (1/2 * 2) (2*4^2) = (1/2) (1) (32) = 16J

so the answer is A right @JoannaBlackwelder

Answer 2

Close. The 2V needs to be squared, not just the V.

Answer 3

oh so it's
A = (1/2) (1) (64) = 32J

so it's C?

Answer 4

Looks right to me :)

Answer 5

woooo thank you!