Respuesta :

Answer:

273.9m/s

Explanation:

Given parameter:

Kinetic energy of the ball  = 4.5kJ

Mass of the ball  = 120g

Unknown:

Speed of the ball  = ?

Solution:

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

 K.E  = [tex]\frac{1}{2}[/tex] m v²

where m is the mass

           v is the speed

Convert the quantities to the appropriate units;

     4.5kJ to J  = 4.5 x 10³J

 120g to kg  = 0.12kg

Now insert the parameters and find the unknown:

       4500  = [tex]\frac{1}{2}[/tex] x 0.12 x V²  

      9000 = 0.12V²  

       V²  = [tex]\frac{9000}{0.12}[/tex]   = 75000

        V  = 273.9m/s