Posted by **Janus** on Saturday, January 23, 2010 at 2:14am.

For a ballistics study a 1.9 gram bullet is fired into soft wood at 380 meters/sec and penetrates 15 cm.

a.) find the retarding force (resistance) in N.

b.) the time needed to stop the bullet in sec.

c. acceleration of the bullet in meters/sec.

- physics -
**drwls**, Saturday, January 23, 2010 at 3:08am
a) initial kinetic energy = (force) x (penetration distance)

Solve for the force, F = .

Use kg and meters for doing the calculation.

b) Vaverage * time = (Vo/2)*time = 0.15 m

Solve for the stopping time.

Vo is the initial velocity, 380 m/s

c) a = F/m = Vo/(stopping time)

(You should get the same answer wither way)

## Answer this Question

## Related Questions

- Physics - A .22 rifle bullet, traveling at 373m/s, strikes a block of soft wood...
- Physics - 1. A bullet of 0.0500 kg is fired into a block of wood. Knowing that ...
- physics - A .22 rifle bullet traveling at 360m/s strikes a block of wood, which ...
- Physics - a point 22 caliber rifle fires a 1.8 gram bullet at a 400m/s into a ...
- physics - a bullet penetrates 7 cm into a block of wood when fired at a speed of...
- physics - A bullet penetrates 7 cm into a block of wood when fired at a speed of...
- Physics - A 5 gram bullet is fired and embeds into a 30 gram block of wood ...
- Physics - A 5 gram bullet is fired and embeds into a 30 gram block of wood ...
- physics - a bullet of mass 0.06kg is fired into a block of wood. if the bullet ...
- Physics - A bullet of mass 0.02kg is fired at a speed of 500m/s towards a fixed ...