Question

A block at rest explodes into three equal parts.Two parts atart moving along X and Y axes respectively with equal parts of 10 m/s.Find the velocity of the third part.

Answer 1

As the block is exploded only due to its internal energy.So,net external force during this process is 0.

So the centre of mass will not change.

Let the body while uploaded was at the origin of the co-ordinate system.

If the two bodies of equal mass is moving at a speed of 10 m/s in +x and +y axis direction respectively,then their resultant will move with velocity.

$\sqrt{{10}^2+{10}^2+\mathrm{2.10.10}cos{90}^{\circ }}=10\sqrt{2}\frac{m}{s}{45}^{\circ }$ w.r.t +x-axis

If the centre of mass is at rest then the thrid mass which have equal mass then two will move in the opposite direction (i.e. 135- w.r.t. +x-axis) of the resultant at the same velocity 10$\sqrt{2}\frac{m}{s}$