A dish of mass 10g is kept horizontally in air by firing bullets of mass 5g each at the rate of 100/s. I the bullets rebound with the same speed,what is the velocity with which bullets are being fired?
Take angle between bullets and dish is 90 degree.
Take angle between bullets and dish is 90 degree.
1 Answer
The dish is being held horizontal in air by volley of bullets fired from below perpendicular to it. Therefore, in equilibrium position downward force due to gravity
Downward force
We know that force
Let velocity of bullet as it collides the dish be
Momentum of single bullet
The bullets collide with the dish elastically, momentum of one bullet after rebound
Change of momentum of one bullet
By Law of Conservation momentum, equal and opposite to this momentum should be transferred to dish.
Setting up of force equation in the equilibrium position for bullets fired at the rate of
#0.0981=0.01vxx100#
#=>v=0.0981/(0.01xx100)#
#=>v=0.0981" ms"^-1#