Question

A body of mass 10 kg is moving with a kinetic energy of 2000 J. The momentum of the body is:
a) 20 kg m/s
b) 200 kg m/s
c) 2000 kg m/s
d) 400 kg m/s

Answer 1

Answer: The initial kinetic energy is 2000 J and the final kinetic energy is 1000 J. If the mass of the body is doubled and it's velocity is halved. Hence, The initial kinetic energy is 2000 J and the final kinetic energy is 1000 J.

Answer 2

Answer:

as

$kinetic \: energy = 1 \div 2 \times m \times {v}^{2}$

therefore,

2000=1/2×10×v^2

${v}^{2} = 400$

$v = 20$

now

p(moment.)=mv

=10×20

=200kg×m/s