# Find the duration of shot

Gold Member

## Homework Statement

A cannon of mass M starts sliding freely down a smooth inclined plane at an angle α to the horizontal. After the cannon covered the distance l, a shot was fired, the shell leaving the cannon in the horizontal direction with a momentum p. As a consequence, the cannon stopped. Assuming the mass of the shell to be negligible, as compared to that of the cannon, determine the duration of the shot.

## Homework Equations

Kinematics Equations
Conservation of Momentum

## The Attempt at a Solution

Acceleration of cannon along incline = $gsinα$
Distance covered = l
Initial Velocity = 0
So final velocity of the cannon (v) = $\sqrt{2glsinα}$
If I take X-axis along the incline and Y-axis perpendicular to it
$\vec{p}_{i}=Mvcosα$
$\vec{p}_{f}=0$ (Since cannon stops)
Since I have to find duration of shot so that means I have to find the time interval during which the momentum of the cannon changed. Am I right with this assumption or does that means something else? If I'm right then how do I find it?

Related Introductory Physics Homework Help News on Phys.org