Transcript Review of Momentum and Impulse

1.
Momentum is often called ________ in
motion
Answer: inertia
2. ______ is measured in kg and is a
component of momentum
Answer: mass
3. _____________ is a vector quantity that is
defined as the rate of change in position
or distance.
Answer: velocity
4. ________ is the rate of change in velocity,
and can be either positive or negative
depending on the direction.
Answer: acceleration
5. Newton’s 1st law refers to this term as
resistance to change in motion.
Answer: inertia
6. _________ is measured in Newtons, this
term is defined as a push or pull and will
result in a change in velocity, therefore a
change in an object’s momentum.
Answer: force
7. __________ is the result of just a force
acting on an object. Think of an egg
cracking when it hits the floor.
Answer: impact
8. _________ is the result of a force over a
period of time acting on an object. Items
like airbags, and padding increase this
and prevent damage to objects as their
momentum is changed.
Answer: impulse
9. This law states that for every action there is
an equal and opposite reaction therefore
this formula below is true, and can be used
to calculate recoil of a gun when a bullet is
shot.
Δmv= Δmv
Answer: Newton’s 3rd
10. This law states that when a force is
applied to an object with mass, the
object will accelerate in the direction of
the force. The formula looks like this
F=ma, or when dealing with impulse
looks like this:
Ft = Δmv
Answer: Newton’s 2nd
11. An object can have momentum even
when it is not moving because it has
mass.
Answer: False, no velocity = no momentum
12. When you increase the amount of time
a force is applied to an object when
stopping it, you will decrease the
amount of force needed.
Answer: True
13. Air bags, crumple zones, and bending
your knees when you land all increase
the force needed to stop.
Answer: False they increase time which
decreases the force needed.
14. When solving for momentum, mass and
momentum have a direct relationship.
Answer: True, if you increase mass you will
increase momentum.
15. An impulse is needed to change
momentum.
Answer: True, you must apply a force to
change velocity Ft= Δmv
16. When an egg is thrown at a wall it
breaks, when an egg is thrown at a sheet
suspended from the ceiling it does not
break, because the sheet applies a
greater force over a shorter period of
time.
Answer: False, the sheet applies less force
over a larger period of time.
17. Calculate the momentum if…
a bowling ball has a mass of 2 kg and is
moving 2 m/s
Answer: 4 kg m/s
18. Calculate velocity if…
An object has a momentum of 10 kg m/s
and a mass of 2 kg.
Answer: 5 m/s
19. Which has more momentum, a missle
with a mass of 500 kg moving at 20 km/hr
or a bullet with a mass of .05 kg moving
at 20000 km/hr?
Answer: the missle has more momentum at
10,000 than the bullet at 1000 kg km/hr
20. Calculate the force needed to stop a
10 kg object moving at 5 m/s in 3
seconds.
Answer: 16.6 N
21. A rifle shoots a 7 gram bullet out of its
barrel at 190 m/s. If the gun has a mass
of 3 kg what is the velocity of the recoil?
Answer: .44 m/s
22. If a van with a mass of 2275 kg is
traveling at 28 m/s rear-ends a car with a
mass of 875 and a speed of 16 m/s, what
is their combined velocity after the crash
if they are stuck together?
Answer: 24.67 m/s
23. A van with a mass of 2275 kg is traveling
at 28 m/s rear-ends a car with a mass of
875 and a speed of 16 m/s, if the speed
of the van is 10 m/s after the collision
what is the speed of the car?
Answer: 62.8 m/s
24. A 0.035 kg bullet strikes a 5 kg stationary
block and embeds itself in the block. The
block and the bullet move together at
8.6 m/s. What is the original velocity of
the bullet?
Answer: 1227.17 m/s
25. A 3000 kg moving truck is traveling east
at 5 km/hr and hits headon a 1000 kg car
traveling west at 10 km/hr. The two
vehicles stick together in the collision
what is the post-collision velocity of the
truck and car?
Answer: 1.25 m/s