# Soldier jumps out of a plane

1. Nov 13, 2015

### sidt36

1. The problem statement, all variables and given/known data

A soldier with a machine gun, falling from an airplane gets detached from his parachute. He is able to resist the downward acceleration if he shoots 40 bullets a second at the speed of 500 m/s. If the weight of a bullet is 49 gm, what is the weight of the man with the gun ? Ignore resistance due to air and assume the acceleration due to gravity g = 9.8 m/s2
2. Relevant equations
acceleration in place of velocity?

3. The attempt at a solution
m_s* v = m_b*v

But how do i get this velocity

2. Nov 13, 2015

### lordianed

You could try to recall the relationship between force and momentum, that would explain how the soldier stays in the air.

3. Nov 13, 2015

### haruspex

He fires one bullet; what is the effect on his velocity? If he does that 40 times a second, what acceleration would that produce?

4. Nov 13, 2015

### sidt36

I think i have it

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5. Nov 13, 2015

### SteamKing

Staff Emeritus
Yellow text on a white background is going to burn someone's eyes out.

6. Nov 14, 2015

### J Hann

How did you get 49 in your solution since 49 gm / bullet = .049 kg / bullet?

7. Nov 15, 2015

### sidt36

I multiplied it by 1/1000