Transcript AP Sample Questions

Acceleration
 Coefficient of Friction
 Equilibrium
 Force
 Free Body Diagram
 Inertia
 Kinetic Friction
 Mass
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Motion
 Net Force
 Newton
 Rolling Friction
 Static Friction
 Terminal Velocity
 Vector
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Contact – direct
contact or touch
between objects
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Long Range – acts
at a distance
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Pushing a crate across the floor – Applied
Air Friction - Drag
Opposes motion – Friction
Support force – Normal
Created in a rope, etc when connected to
another mass – Tension
Force due to gravity – Weight
Are the forces above contact or long range?
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Pictorial diagram of
all the forces acting
on an object
The length of the
arrow is
proportional to the
magnitude of the
force
How is the normal
force drawn?
How is weight
drawn?
Draw a FBD for the following:
1. A flowerpot falls freely from a windowsill.
2. A skydiver falls at a constant velocity.
3. A cable pulls a box across a table. The box
accelerates even though friction is present.
4. A rope lifts a bucket.
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The vector sum of all forces acting on an
object
Calculated for both the x and the y
Represented by ΣF
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Pictorial diagram of
all the forces acting
on an object
The length of the
arrow is
proportional to the
magnitude of the
force
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Law of Inertia
An object at rest will stay at rest, an object in
motion will stay in motion unless acted upon
by an unbalanced force greater than zero
Ex. A car rider continues forward when the
driver suddenly applies the brakes
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∑F = ma
W = mg
Ff = µFn
What is the net force?
What is the unit for mass?
Is mass the same quantity as weight?
What is g?
What is μ?
On a flat surface, what is equal to the Fn ?
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If all of the forces acting on an object balance so
that the net force is zero, then
A. The object must be at rest
B. The object must be at a constant velocity
C. The object may be at rest or at a constant
velocity
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Two astronauts tug on opposite sides of a satellite.
The first astronaut tugs to the left with a force of
30 N. With what force does the second astronaut
tug in order to keep the satellite moving toward
him at a constant velocity of 20 m/s?
A. 30 N
B. – 30 N
C. 0 N
D. 50 N
E. 1.5 N
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The maximum (or terminal) velocity of a
skydiver (m=70kg) with arms and legs
extended is about 120 mi/h (= 53.6 m/s).
What force does air resistance exert on the
skydiver?
A. 0 N
B. 13 N
C. 70 N
D. 700 N
E. 1000 N
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An airplane has a mass of 3.1 x 104 kg and
takes off under the influence of a constant
net force of 3.7 x 104 N. What is the
acceleration that acts on the plane?
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Weight and mass are
A. always the same
B. inversely proportional
C. based on location
D. none of the above
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A large (150 kg) refrigerator needs to be
moved across the kitchen. Fred pulls with a
force of 100 N and Wilma pulls with 75 N in
the same direction. If the force of friction
was 40 N, what will be the acceleration of
the refrigerator?
A 1.17 m/s2
B 0.90 m/s2
C 0.43 m/s2
D 135 m/s2
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When a parachutist jumps from an airplane, he
eventually reaches a constant speed, called the
terminal velocity. This means that
a. the acceleration is equal to g.
b. the force of air resistance is equal to zero.
c. the effect of gravity has died down.
d. the effect of gravity increases as he becomes
closer to the ground.
e. the force of air resistance is equal to the weight
of the parachutist.
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The force of kinetic friction is always
__________ than the force of static friction.
a. less than
b. equal to
c. greater than
d. varies depending on situation
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The normal force acts ______________ to the
surface of the contact object
a. perpendicular
b. parallel
c. at an angle
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For every action, there is an equal and
opposite reaction
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A mass is suspended on a spring. The
reaction force to the force of the gravity from
the Earth acting on the mass is the force
exerted by the
A. mass on the Earth
B. mass on the spring
C. spring on the mass
D. spring on the Earth
E. Earth on the mass