A man standing on a frictionless horizontal surface fires a machine gun. Projecting bullets of mass $10 g$ each at the rate of 3 bullets per second horizontally at muzzel speed of $300 m / s$ . Velocity of man after 2 seconds of 1st fire is $5 n c m / s$ , then $n$ is (Mass of man is 60 kg)

Open in App

Solution

$F_{t} = V \frac{d m}{d t} = 300 \times 30 - - - \times 10^{- 3} N = 9 N a = \frac{F_{t}}{m} = \frac{9}{60} m / s^{2} \Rightarrow v = u + a t v = 0 + \frac{9}{60} \times 2 = \frac{3}{10} = 30 c m / s$

Suggest Corrections

Similar questions

Q. A machine gun is mounted on a

2000 k g

car on a horizontal frictionless surface. At some instant, the gun fires

10

bullets/second, each of mass

10 g

with a velocity of

500 m s^{- 1}

. The acceleration of the car is:

Q. A machine gun is mounted on a

2000 k g

car on a horizontal frictionless surface. At some instant the gun fires bullets of mass

10 g

with a velocity of

500 m / s e c

with respect to the car. The number of bullets fired per second is ten. The average thrust on the system is:

Q. A machine gun fires a bullet of mass

40 g

with a velocity

1200 m/s

. The man holding it can exert a maximum force of

144 N

on the gun. How many bullets can be fired per second at most?

A machine gun is mounted on a 2000 kg car on a horizontal frictionless surface. At some instant the gun fires bullets of mass 10 gm with a velocity of 500m/ s with respect to the car . The number of bullets fired per second is ten. The average thrust on the system is ??

Q. A machine gun is mounted on a 2000 kg car on a horizontal frictionless surface. At some instant, the gun fires 10 bullets/second, each of mass 10 g with a velocity of 500 m s

^{- 1}

. The acceleration of the car is

Join BYJU'S Learning Program

A man standing on a frictionless horizontal surface fires a machine gun. Projecting bullets of mass 10 g each at the rate of 3 bullets per second horizontally at muzzel speed of 300 m/s . Velocity of man after 2 seconds of 1st fire is 5n cm/s, then n is (Mass of man is 60 kg)

Ft=Vdmdt=300×30–––×10−3N=9 Na=Ftm=960 m/s2⇒v=u+atv=0+960×2=310=30 cm/s

A man standing on a frictionless horizontal surface fires a machine gun. Projecting bullets of mass $10 g$ each at the rate of 3 bullets per second horizontally at muzzel speed of $300 m / s$ . Velocity of man after 2 seconds of 1st fire is $5 n c m / s$ , then $n$ is (Mass of man is 60 kg)

$F_{t} = V \frac{d m}{d t} = 300 \times 30 - - - \times 10^{- 3} N = 9 N a = \frac{F_{t}}{m} = \frac{9}{60} m / s^{2} \Rightarrow v = u + a t v = 0 + \frac{9}{60} \times 2 = \frac{3}{10} = 30 c m / s$