Download Momentum_Jeopardy

Physics Is
Phun!
Momentum
Impulse
Collisions
Conservation
of Momentum
5 pt
5 pt
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5 pt
10 pt
10 pt
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15 pt
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20 pt
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25 pt
25 pt
25 pt
25 pt
25 1pt
How do you calculate the momentum
of an object?
2
How do you calculate the momentum
of an object?
Momentum = Mass x Velocity
3
True or False: Momentum is a
vector quantity.
4
True or False: Momentum is a
vector quantity.
True
5
What is the momentum of a 0.520-kg
object moving at a velocity of 14 m/s?
6
What is the momentum of a 0.520-kg
object moving at a velocity of 14 m/s?
Momentum = Mass x Velocity
p = mv = (0.520 kg)(14 m/s)
p = 7.28 kg m/sec
7
Of the object’s listed, select the one with
the greatest momentum.
A) a .22-caliber bullet fired from a rifle
B) a bus speeding along a highway
C) a sprinter running the 100-yard dash
D) the Earth in its orbit
E) not enough info to answer
8
Of the object’s listed, select the one with
the greatest momentum.
A) a .22-caliber bullet fired from a rifle
B) a bus speeding along a highway
C) a sprinter running the 100-yard dash
D) the Earth in its orbit
E) not enough info to answer
9
What is the total momentum of the following
situation? Assume there is no friction.
1.5 m/s
2 kg
0.8 m/s
3 kg
10
What is the total momentum of the following
situation? Assume there is no friction.
1.5 m/s
0.8 m/s
2 kg
3 kg
Momentum of LH-cart = (2 kg)(1.5 m/s) = + 3 kg m/sec
Momentum of RH-cart = (3 kg)(- 0.8 m/s) = - 2.4 kg m/sec
Total Momentum = + 3 kg m/sec – 2.4 kg m/sec
= 0.6 kg m/sec
11
An impulse is equal to which of the
following?
A)
B)
C)
D)
E)
force times distance
energy
change in kinetic energy
change in momentum
none of these
12
An impulse is equal to which of the
following?
A)
B)
C)
D)
E)
force times distance
energy
change in kinetic energy
change in momentum
none of these
13
If a boxer wishes to reduce the
force of impact from an
incoming punch, what should
they do to the time of impact?
14
If a boxer wishes to reduce the
force of impact from an
incoming punch, what should
they do to the time of impact?
Increase the time of impact
15
What is the change in momentum
(impulse) of a soccer ball that is
kicked with a force of 75-N over a
time of 0.18 seconds?
16
What is the change in momentum
(impulse) of a soccer ball that is
kicked with a force of 75-N over a
time of 0.18 seconds?
Change in momentum = impulse = F t
F t = (75 N)(0.18 sec)
F t = 13.5 N sec
17
A bus and a bug are traveling towards
one another when they collide headon. Which one experiences the greater
impulse?
A)
B)
C)
D)
the bus
the bug
they both experience the same impulse
not enough info
18
A bus and bug are traveling towards one
another when they collide head-on.
Which one experiences the greater
impulse?
A)
B)
C)
D)
the bus
the bug
they both experience the same impulse
not enough info
19
A 1,000 kg rocket is launched from rest to
a speed of 2500 m/sec in a time of 2.5
minutes. What was the average force (in
Newtons) exerted on the rocket?
20
A 1,000 kg rocket is launched from rest to
a speed of 2500 m/sec in a time of 2.5
minutes. What was the average force (in
Newtons) exerted on the rocket?
Change in momentum = Impulse
m v = F t ==> F = m v / t
F = (1000 kg)(2500 m/sec)/(150 sec)
F = 16,667 Newtons
21
True or False:
Momentum is conserved in every kind of
collision.
22
True or False:
Momentum is conserved in every
kind of collision.
True
23
Which kind of collision conserves both
momentum and kinetic energy?
A)
B)
C)
D)
elastic
inelastic
both
neither-only momentum is conserved
24
Which kind of collision conserves both
momentum and kinetic energy?
A)
B)
C)
D)
elastic
inelastic
both
neither-only momentum is conserved
25
Why is it safer to stop an out-ofcontrol car by running into a pond
versus hitting a concrete wall?
26
Why is it safer to stop an out-ofcontrol car by running into a pond
versus hitting a concrete wall?
By running into the pond, the time it
takes the car to slow down to a stop
is lengthened. Therefore the
stopping force is decreased.
27
Why is it that a bouncing collision is
more damaging than a sticking
collision (assuming the same time of
impact in each case)?
28
Why is it that a bouncing collision is
more damaging than a sticking
collision (assuming the same time of
impact in each case)?
A bouncing collision is more damaging
because the change in velocity, and
therefore the change in momentum, is
greater. This leads to a larger force.
29
A 0.25 kg softball is hit with a bat. The
incoming velocity of the ball is +25 m/sec
and the outgoing velocity is - 20 m/sec. If
the time of contact is 0.078 sec, what was
the force of impact?
30
A 0.25 kg softball is hit with a bat. The
incoming velocity of the ball is +25 m/sec
and the outgoing velocity is - 20 m/sec. If
the time of contact is 0.078 sec, what was
the force of impact?
Impulse = Change in Momentum
F t = m v ==> F = m v / t
F = (0.25 kg)(45 m/sec)/(0.078 sec)
F = 144.2 Newtons
31
When an asteroid collides with the
moon, the moon drastically changes the
momentum of the asteroid. By how
much does the Moon change its
momentum?
32
When an asteroid collides with the
moon, the moon drastically changes the
momentum of the asteroid. By how
much does the Moon change its
momentum?
Precisely the same amount
33
A firecracker is sitting on the ground
when it is lit. After the explosion, what
is the total momentum of the pieces
flying apart?
34
A firecracker is sitting on the ground
when it is lit. After the explosion, what
is the total momentum of the pieces
flying apart?
Zero, because the momentum of the
firecracker before the explosion was zero,
and momentum must be conserved.
35
A bullet is fired from a heavy rifle.
Two questions:
Which one experiences a greater
change in momentum?
Which one experiences a greater
change in velocity?
36
A bullet is fired from a heavy rifle.
Two questions:
Which one experiences a greater
change in momentum?
Neither, it’s the same
Which one experiences a greater
change in velocity?
The bullet.
37
Two billiard balls collide elastically
on a table as shown below.
Which picture best represents the
motion of ball #2 after the collision?
B
#2
Bonk!
A
#1
C
#1
38
Two billiard balls collide elastically
on a table as shown below.
Which picture best represents the
motion of ball #2 after the collision?
B
#2
Bonk!
A
#1
C
#1
39
Two carts collide as shown below and stick
together. What is the velocity of the carts after
they’ve collided? Assume there is no friction.
6 m/s
3 kg
4 m/s
2 kg
40
Two carts collide as shown below and stick
together. What is the velocity of the carts after
they’ve collided? Assume there is no friction.
.
6 m/s
4 m/s
3 kg
2 kg
Momentum of LH-cart = (3 kg)(6 m/s) = +18 kg m/s
Momentum of RH-cart = (2 kg)(-4 m/s) = -8 kg m/s
Total Momentum = +10 kg m/s
After collision ==> 10 kg m/s = (5 kg)v
v = (10 kg m/s)/(5 kg) = +2 m/sec (to the right)
41
How many triangles are there
in the following figure?
42
35
43
Spock would often raise his right
hand with the fingers splayed
apart and say…
“Live long and _________.”
Also, what was his “race?”
44
“Live long and prosper.”
And
He was a Vulcan
45
What team did arguably the
best baseball player of all
time play for before the NY
Yankees?
46
George Herman (the Babe)
Ruth
47
What California gold-rush
entrepreneur used his
knowledge of bouncing
collisions to design a nearly
90% efficient water wheel?
48
Lester A. Pelton, inventor of
the Pelton water wheel
49
Who is the head coach of Mr.
Bruce’s favorite college
football team?
Hint: Until 2009, they were almost
unbeatable!
50
USC – Lane Kiffin
51