Question

The kinetic energy of an object of mass m, moving with a velocity of 10 m/s is 25 J.
What will be its kinetic energy when its velocity is halved? What will be it's kinetic
energy when its velocity is increased by 5 times?

Answer 1

Answer:

Kinetic energy of an object is 25 J.

Mass of object is m

Velocity of the object is 10m/s

Now 1/2*m*v²= 25

or m= 25*2/10*10

or m= 1/2= 0.5

When velocity is halved i.e velocity is 5m/s

Kinetic energy = 1/2*5*5*1/2

= 25/4

= 6.25 J

When velocity increase by 5 times, velocity is 50 m/s

Kinetic energy = 1/2*1/2*50*50

= 25*25

= 625 J

Answer 2

Explanation:

kinetic energy = 25 J

Velocity = 10 m/s

mass = m

# if velocity is halved = 10/2 = 5 m/s

kinetic energy = ½ mv²

=½ m (5)² J

=25/2 m J

= 12.5m J

# if Velocity is increased 5 times = 10 (5)

kinetic energy= ½ mv²

= ½ m (50)² J

= 2500/2m J

= 1250m J