Answer:
Ball D. Among the four balls in this picture, ball D is the only one whose kinetic energy is greater than
.
Explanation:
Consider an object of mass
. If this object is moving at a speed of
, the kinetic energy of this object would be:
.
The speed
of ball A, B, and C are all
. Hence, the kinetic energy of these three balls would be
.
The speed of ball D is greater than
:
. The kinetic energy of this ball would be:
.
Hence, the kinetic energy of ball D is the greatest among the four balls in this picture.