A .22 rifle bullet traveling at 360m/s strikes a block of wood, which penetrates to a depth of .110m. The mass of the bullet is 1.80g. Assume a constant retarding force.A) how much time is required for the bullet to stop? b) what force in newtons soes the wood exert on the bullet?

Question

a) should have been 6.11X10^-4 s
b) should have been 1060N
For a) I tried using v=d/t for time and for b) I used f=ma to find the force. What am I doing incorrectly?

The average force on the wood * distance= KE of the bullet

F*.11= 1/2 .0018*360^2

That will give you the average force.

time? avgvelocity*time= distance
1/2 360 * time= .110
Time= you do it.

Hi Bob
Care to elaborate on that clock question that I left you a note on below? I don't get it. I'm dying with curosity.

Answer 1

You can get the answer of time by having this formula :

x = 1/2 (v0-v)a.t

just transpose it. . . . .

a= 9.806 m/s^2