Question

3000 kg canon rests on a frozen pond. A shell of 30 kg is fired from the canon horizontally.
If the canon recoils with the velocity of 1.8 m/s, what is the velocity of the shell just after it​

Answer 1

Answer:

Answer depends on principal of conservation of momentum.. i.e. total momentum remains unchanged.

Now before firing, both were at rest..

and since momentum(p) = m•v,

Total initial momentum = 0.

So, Total Final Momentum should be Zero(0).

i.e. m1•v1 + m2•v2 = 0,

where 1refers to canon & 2 refers to shell..

Now, direction of canon & shell movement are opposite.. so will be the direction of there velocities..

let v1 = 1.8m/s.. So, v2 = (-)V

So, m1•v1 - m2•V = 0

or, m1•v1 = m2•V

Or, V = (m1•v1)/m2 = (3000•1.8)/30

Or, V = 180m/s