Question

If a football player throws a ball that has a kinetic energy of 1225 j and the ball has a mass of 2 kg, how fast is the ball going?

Answer 1

given,

kinetic energy of ball = 1225 J

mass of ball = 2kg

to find: speed of the ball

solution:

Kinetic energy is the energy possessed by a body by virtue of its motion.

or, K.E = (1/2)*m*v^2

Substituting the values,

1225= (1/2 *)*2 * v²

or, v² = 1225

or, v = √1225

or, v = 35 m/s

therefore, the ball will be going by speed of 35 m/s.

Answer 2

Given

• Kinetic energy (K.E) = 1225 J

• Mass (m) = 2 Kg

To find

• Velocity (v)

Solution

• K.E = 1/2 mv²
• 1225 = 1/2 2v²
• v² = 1225 × 2/2
• v² = 1225
• v = √1225
• v = 35

Hence, the velocity of the ball is 35 m/s