Question

A 2.45 g table tennis ball has the KE of 31.5 J. At what velocity is the tennis ball traveling?

Answer 1

Answer:

160.35 m/s

Explanation:

Kinetic energy of a body depends on the mass (m) of the body and the speed (v) with it is moving. It is the energy possessed by body due to virtue of its motion.

K.E. = 0.5 m v²

It is given that, m = 2.45 g = 2.45 ×10⁻³ kg

K.E. = 31.5 J

$v = \sqrt{\frac{2K.E.}{m}} = \sqrt{2\times 31.5}{2.45 \times 10^{-3}}=160.35 m/s$

Thus, the tennis ball is moving with the velocity of 160.35 m/s.

Answer 2

KE =
$\frac{1}{2} mv {}^{2}$
Convert g in kg
Find v:
2KE = mv^2
v=√2KE/m
v=√2*31.5/0.00245
v=160 m/s