Lecture­Momentum Cannon.notebook
November 25, 2012
Consider the following:
Please
Log In
Lecture­Momentum Cannon.notebook
November 25, 2012
Lecture­Momentum Cannon.notebook
November 25, 2012
Lecture­Momentum Cannon.notebook
November 25, 2012
How does the momentum of the cannon and cannon ball system before it is fired compare to after the cannon is fired?
1
A C BD Start
Question
a)
b)
c)
d)
It is greater
It is less
It is the same
It is incomparable
Lecture­Momentum Cannon.notebook
November 25, 2012
How does the momentum of the cannon and cannon ball system before it is fired compare to after the cannon is fired?
a)
b)
c)
d)
It is greater
It is less
It is the same
It is incomparable
Lecture­Momentum Cannon.notebook
November 25, 2012
How does the momentum of the cannon and cannon ball system before it is fired compare to after the cannon is fired?
Pball = m v
Pcannon = m v
0 = Pcannon + Pball
(Pcannon = ­Pball )
a)
b)
c)
d)
It is greater
It is less
It is the same
It is incomparable
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = pc + pb
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = pc + pb
∴ pc = ­pb
pc
pb
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = pc + pb
∴ pc = ­pb
pc
pb
mcvc = ­mbvb
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = pc + pb
∴ pc = ­pb
pc
pb
mcvc = ­mbvb
(1000 kg)vc = ­(10 kg)(400m /s)
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
pc
pb
mcvc = ­mbvb
(1000 kg)vc = ­(10 kg)(400m /s)
0 kg m /s = pafter
0 kg m /s = pc + pb
∴ pc = ­pb
­(10kg)(400m /s)
vc =
1000 kg
Lecture­Momentum Cannon.notebook
November 25, 2012
Cannon (1000kg) fires a cannonball (10kg) at 400m/s. What is the velocity of the cannon?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
pc
pb
mcvc = ­mbvb
(1000 kg)vc = ­(10 kg)(400m /s)
0 kg m /s = pafter
0 kg m /s = pc + pb
­(10kg)(400m /s)
vc =
1000 kg
∴ pc = ­pb
vc = ­4 m /s
Lecture­Momentum Cannon.notebook
November 25, 2012
Senteo TIME!!!
Title Page
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon 1 Cannon velocity?
when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
A M
R
K
T
E
O
W
3 Sig Figs
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with what you know:
pbefore = pafter
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = p1 + p2
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = p1 + p2
∴ p1 = ­p2
p1
p2
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with m1 v1 = ­m2 v2
what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = p1 + p2
∴ p1 = ­p2
p1
p2
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with m1 v1 = ­m2 v2
what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = p1 + p2
∴ p1 = ­p2
(mcannon + mBob )v1 = ­m2 v2
p1
p2
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with m1 v1 = ­m2 v2
what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = p1 + p2
∴ p1 = ­p2
(mcannon + mBob )v1 = ­m2 v2
p1
p2
­m2v2
v1 = (m
cannon + mBob )
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with m1 v1 = ­m2 v2
what you know:
pbefore = pafter
pbefore = 0 kg m /s
0 kg m /s = pafter
0 kg m /s = p1 + p2
∴ p1 = ­p2
(mcannon + mBob )v1 = ­m2 v2
p1
p2
­m2v2
v1 = (m
cannon + mBob )
­(10 kg)(400.2 m /s)
v1 =
(1000 kg + 100 kg)
Lecture­Momentum Cannon.notebook
November 25, 2012
Sideshow Bob, who has a mass of 100 kg, sits on the 1000 kg cannon when it’s fired. The 10 kg cannonball moves at 400.2 m/s. What is the velocity of the cannon when it’s fired?
Start with m1 v1 = ­m2 v2
what you know:
pbefore = pafter
pbefore = 0 kg m /s
(mcannon + mBob )v1 = ­m2 v2
p1
p2
­m2v2
v1 = (m
cannon + mBob )
0 kg m /s = pafter
0 kg m /s = p1 + p2
∴ p1 = ­p2
v1 = ­3.64 m/s
­(10 kg)(400.2 m /s)
v1 =
(1000 kg + 100 kg)
Lecture­Momentum Cannon.notebook
November 25, 2012
Now we add an external force: friction
Pcannon = m v
Friction
Pball = m v
Lecture­Momentum Cannon.notebook
November 25, 2012
Now we add an external force: friction
Friction is the force that changes the momentum of the cannon. Pcannon = m v
Pball = m v
Pcannon ≠ Pball
Friction
Impulse = Change in Momentum
(Ft = Δmv)