The mass of a cannon is 500 kg. From this cannon a bullet of 10 kg mass was thrown at a speed of 20 m / s. How long does a cannon retreat if the resistance of the land is one tenth the weight of the cannon?

### Asked by asishsengupta51 | 20th Feb, 2020, 11:24: AM

Expert Answer:

### By conservation of momentum, we get initial speed of cannon as , M V = - m v
where M = 500 kg is mass of canon, V is its initial speed , m is mass of bullet = 10 kg and v = 20 m/s is speed of bullet.
we get V = - 10 × 20 / 500 = - 0.4 m/s
if the resistance given by land is (1/10)th weight, i.e. resistive force = (1/10) × 500 × 9.8 N = 490 N
Retardation = force/mass = 490/500 = 0.98 m/s^{2}
Hence distance S travelled by cannon while firing bullet is obtained from , v^{2} = u^{2} - 2aS
where v is final speed wich is zero here, u is inital speed and a is retardation
Hence S = u^{2} / (2a) = ( 0.4 × 0.4 ) / ( 2 × .98 ) = 0.081 m = 8.1 cm

^{2}

^{2}= u

^{2}- 2aS

^{2}/ (2a) = ( 0.4 × 0.4 ) / ( 2 × .98 ) = 0.081 m = 8.1 cm

### Answered by Thiyagarajan K | 22nd Feb, 2020, 11:18: AM

## Application Videos

## Concept Videos

- what is linear momentum ?
- a bullet of mass 20 grams is horizontally fired with a volicity of 150 mls from pistal of mass 2 kg what is the recoil volicity of pistal
- Two hockey players of opposite teams, while trying to hit a hockey ball on the ground collide and immediately become entangled. One has a mass of 60 kg and was moving with a velocity 5.0 m s–1 while the other has a mass of 55 kg and was moving faster with a velocity 6.0 m s–1 towards the first player. In which direction and with what velocity will they move after they become entangled? Assume that the frictional force acting between the feet of the two players and ground is negligible.
- vehicle stops on applying brakes does this phenomena violate the principle of conservation of momentum momentum momentum
- please answer fast
- question number 33
- A bullet of mass 3 kg is fired with a velocity of 150 metre per second find its momentum
- A ball moving at a constant speed 10m/s, hits normally on a wall (mass of ball is 50g) and rebounds with same speed. The change in momentum is
- What is the meaning of: p=mu and p=mv Are they equal?

### Kindly Sign up for a personalised experience

- Ask Study Doubts
- Sample Papers
- Past Year Papers
- Textbook Solutions

#### Sign Up

#### Verify mobile number

Enter the OTP sent to your number

Change