Question

19

Answer 1

Answer: The mass of ball is 10 grams.

Explanation:

Given : Kinetic energy = 4.5 J

Velocity = 30 m/s

The formula for Kinetic energy is as follows.

$K.E = \frac{1}{2}mv^{2}$

where,

K.E = Kinetic energy

m = mass

v = velocity

Substitute the values into above formula as follows.

$K.E = \frac{1}{2}mv^{2}\\4.5 J = \frac{1}{2} \times m \times (30 m/s)^{2}\\m = \frac{4.5 J \times 2}{900 m^2/s^2} (1 Js^{2} = kg m^{2})\\= 0.01 kg (1 kg = 1000 g)\\= 10 g$

Thus, we can conclude that the mass of ball is 10 grams.