A ball has a kinetic energy of 4.50 kJ. If the ball has a mass of 120.0 g, how fast is the ball traveling, in meters per second?

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  = 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  = x 0.12 x V²  

      9000 = 0.12V²  

       V²  =   = 75000

        V  = 273.9m/s

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