- #1
bob1182006
- 492
- 1
Not really homework but doing all problems in the book this one just stumped me...
A pellet gun finers ten 2.14-g pellets per second with a speed of 483 m/s. The pellets are stopped by a rigid wall
(a) Find the momentum of each pellet.
(b) Calculate the average force exerted by the stream of pellets on the wall.
(c) If each pellet is in contact with the wall for 1.25 ms, what is the average force exerted on the wall by each pellet while in contact? Why is this so different from (b)?
P=mv
P2-P1=Favg*(t2-t1)
[tex](a) P=m_pv_p=1.03kg*m/s[/tex]
(b) ok the "stream" screws me up, wouldn't the average force of the stream be the average force of just 1? it's just that it's one after the other etc...
[tex]F_{avg}=\frac{P_2-P_1}{\Delta t}=\frac{m_P(V_f-V_i)}{\Delta t}[/tex]
I don't know a delta t, final velocity=0?
(c)[tex]f_{avg}=\frac{m_P(V_f-V_i)}{\Delta t}=\frac{-483*2.14*10^-3}{1.25*10^{-3}}=-826.9N[/tex]
this is force from bullet to wall, wall to bullet = 826.9N
Homework Statement
A pellet gun finers ten 2.14-g pellets per second with a speed of 483 m/s. The pellets are stopped by a rigid wall
(a) Find the momentum of each pellet.
(b) Calculate the average force exerted by the stream of pellets on the wall.
(c) If each pellet is in contact with the wall for 1.25 ms, what is the average force exerted on the wall by each pellet while in contact? Why is this so different from (b)?
Homework Equations
P=mv
P2-P1=Favg*(t2-t1)
The Attempt at a Solution
[tex](a) P=m_pv_p=1.03kg*m/s[/tex]
(b) ok the "stream" screws me up, wouldn't the average force of the stream be the average force of just 1? it's just that it's one after the other etc...
[tex]F_{avg}=\frac{P_2-P_1}{\Delta t}=\frac{m_P(V_f-V_i)}{\Delta t}[/tex]
I don't know a delta t, final velocity=0?
(c)[tex]f_{avg}=\frac{m_P(V_f-V_i)}{\Delta t}=\frac{-483*2.14*10^-3}{1.25*10^{-3}}=-826.9N[/tex]
this is force from bullet to wall, wall to bullet = 826.9N