Question 363: Centre of Mass and Rotational Motion

Question

A particle of mass $$10 \mathrm{~kg}$$ moving eastwards with a speed $$10 \mathrm{~m} / \mathrm{s}$$ collides with another particle of the same mass moving northward with the same speed $$10 \mathrm{~m} / \mathrm{s}$$. The two particles coalesce on collision. The new particle of mass $$20 \mathrm{~kg}$$ will move in the north-east direction with velocity.

Accepted Answer

Here, initial momentum of particle $$=$$ Final momentum of particles,
$$m v \hat{\mathbf{i}}+m v \hat{\mathbf{j}}=2 m v$$
Where, $$\mathbf{v}=\frac{v}{2}(\hat{\mathbf{i}}+\hat{\mathbf{j}})$$
Hence, $$v=\frac{v}{2} 	imes \sqrt{2}=v / \sqrt{2} \quad\left(\because v=10 \mathrm{~ms}^{-1}ight)$$
So, $$v=\frac{10}{\sqrt{2}} \mathrm{~ms}^{-1}$$

Answer

$$10 \mathrm{~m} / \mathrm{s}$$

Answer

$$5 \mathrm{~m} / \mathrm{s}$$

Answer

$$10 / \sqrt{2} \mathrm{~m} / \mathrm{s}$$

Answer

None

Centre of Mass and Rotational Motion

Choose the correct answer: