Question

1) What is the reason that we burn out our body fat only when we walk briskly? Why does normal walking not burn out the same amount of body fat when the distance covered remains the same?

2) Two bodies of masses $m_{1}$ and $m_{2}$ have equal kinetic energies. If $p_ {1}$ and $p_{2}$ are their respective momentum, then ratio $p_{1}:p_{2}$ is equal to (answer should come $\sqrt{ m_{1} } : \sqrt{ m_{2} }$)

3) A light and a heavy body have equal kinetic energy. Which one has a grater momentum?
(answer should come the heavy body)

Answer 1

perhaps because when we walk we use a little force in pushing us forward. When we walk briskly, we exert more force on ground and ground exerts the same force on us.

Work done  = force * distance
So more work done when we exert more force , as the distance is same.
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KE = p₁²/2m₁  = p₂²  / 2 m₂

p₁²/p₂² = m₁/m₂
p₁/p₂ = √m₁/√m₂
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2 m₁ * KE  = p₁²
2 m₂ * KE = p₂²
     hence,  If m₁ > m₂,  then  p₁ > p₂