Question

The velocity of a body of mass 60 kg reaches 15 m/s from 0 m/s in 12 Seconds Calculate the k.E​

Answer 1

Answer:

3000J

Explanation:

u= 15 m/s

mass(m) = 60kg

v= 5 m/s

t=12 sec

K.E = 1/2(mass)x((velocity)square)

=1/2 (15-5)x(15-5)x60

= 1/2 x 10x 10x60

= 30x100

= 3000J

Answer 2

Answer:

Given , Mass of object, m=10 kg

Velocity of object, v=20ms

−1

Initial Kinetic energy, K

1

=

2

1

×10×20

2

=2000 J

Now, Final mass, m

2

=20 kg

Final Velocity, v

2

=10m/s

Final Kinetic energy, K

2

=

2

1

×20×10

2

=1000 J

Required Ratio =

K

2

K

1

=

1000

2000

=2:1