Question

C

Answer 1

Answer:

27J  

3528J

Explanation:

First problem:

Given parameters:

Mass of tennis ball  = 0.06kg

Velocity of tennis ball  = 30m/s

Unknown:

Kinetic energy  = ?

Solution:

Kinetic energy is the energy due to the motion of a body.

It is expressed as:

       K.E  = $\frac{1}{2}$ m v²  

       K.E =  $\frac{1}{2}$  x 0.06 x 30²   = 27J  

Second problem:

Given parameters:

Mass = 30kg

Height  = 12m

Unknown:

Potential energy  = ?

Solution:

Potential energy is the energy due to the position of a body.

  Mathematically;

       Potential energy  = mgh

m is the mass

g is the acceleration due to gravity

h is the height

 Now;

          Potential energy  = 30 x 9.8 x 12  = 3528J