Dhiren M Doshi Solutions for Chapter: Force and Laws of Motion, Exercise 4: Check Your Progress

State Newton's third law of motion.

Explain the following giving suitable reasons.

We press the ground while walking.

Explain the following giving suitable reasons:

A rubber ball rebounds when struck against a hard floor.

Discuss the conservation of momentum in the case given below:

Recoil of gun when fired.

Discuss the conservation of momentum in each of the following cases:

Launching of rocket from the ground.

A bullet of mass $10 \mathrm{g}$ moving with a velocity of $400 \mathrm{m}/\mathrm{s}$ gets embedded in a freely suspended wooden block of mass $900 \mathrm{g}$. What is the velocity acquired by the block?

A hunter fires a bullet of mass $10 \mathrm{g}$ with a velocity of $400 \mathrm{m}/\mathrm{s}$ from a gun of mass $5 \mathrm{kg}$. What will be the recoil velocity of the gun?

An object of mass $2 \mathrm{kg}$ travelling along a straight line with a velocity of $5 \mathrm{m}/\mathrm{s}$ collides with and sticks to a stationary wooden block of mass $8 \mathrm{kg}$. Then they both move off together in the same straight line. Calculate the total momentum just before the impact and just after the impact. Also calculate the velocity of the combined object.