Download A vector is a quantity that has A. magnitude, only B. direction, only C

A vector is a quantity that has
A.
magnitude, only
B.
direction, only
C.
either magnitude or direction
D. both magnitude and direction
The accompanying vector represents the resultant of two forces acting concurrently on an object at
point P.
Which pair of vectors best represents two concurrent forces that combine to produce this resultant force
vector?
A.
B.
C.
D.
Base your answer(s) to the following question(s) on the information and diagram below.
The diagram shows the top view of a 65-kilogram student at point A on an amusement park
ride. The ride spins the student in a horizontal circle of radius 2.5 meters, at a constant speed of
8.6 meters per second. The oor is lowered and the student remains against the wall without
falling to the oor.
Which vector best represents the direction of the centripetal acceleration of the student at point A?
A.
B.
C.
D.
Which velocity-time graph represents the motion of an object moving with constant acceleration?
A.
B.
C.
D.
The velocity of a car changes from 60 meters per second north to 45 meters per second north in
5.0 seconds. The magnitude of the car's acceleration is
A.
9.8 m/s2
B.
15 m/s2
C.
3.0 m/s2
D. 53 m/s2
The graph represents the relationship between speed and time for a car moving in a straight line. The
magnitude of the car's acceleration is
A.
1.0 m/s2
B.
0.10 m/s2
C.
10 m/s2
D. 0.0 m/s2
Susan gently pushes the tip of her nger against the eraser on her pencil and the pencil does not move.
Which of the following gures best illustrates the interaction of forces between Susan's nger and her
pencil?
A.
B.
C.
D.
Two students are pushing a cart, as shown below.
The cart will move as if it were acted on by a single force with a magnitude of
A.
50 N.
B.
150 N.
C.
200 N.
D. 350 N.
Driving Home Newton's Laws of Motion
Automobiles, baseballs, skateboards and bicycles — the world is full of things that are in motion. Centuries ago the
British physicist Sir Isaac Newton stated three laws that describe the ways in which things move. These are Newton's
three laws of motion:
The rst law: Unless acted upon by an outside force, a body at rest
tends to stay at rest, and a body in motion tends to stay in motion.
The second law: Acceleration is equal to the net force acting on a
body divided by its mass.
The third law: For every action force there is an equal and opposite
reaction force.
A driver starts her car and steps on the gas pedal. The car gradually accelerates to 50 km/hr. A few minutes later, the
driver suddenly slams on the brakes to avoid hitting a box in the road. As the car comes to a stop, the driver's body
appears to lurch forward in the seat until it is restrained by the seatbelt.
What law best explains why the driver's body appears to lurch forward when the brakes are suddenly applied?
A.
Newton's rst law
B.
Newton's second law
C.
Newton's third law
D. The law of gravity
If each horse is pulling with the same force, in which direction will the rock move?
A.
north
B.
east
C.
south
D. west
The tendency of a stationary object to resist being put into motion is known as
A.
acceleration.
B.
inertia.
C.
weight.
D. velocity.
A student researches Jupiter and Saturn and records the following information:
Jupiter is about half the distance to the Sun that Saturn is.
Jupiter is about three times more massive than Saturn.
Based on this information, which of the following can be concluded about the gravitational forces
between these planets and the Sun?
A.
There are no gravitational forces between Jupiter and the Sun or between Saturn and the Sun.
B.
There are equal gravitational forces between Saturn and the Sun and between Jupiter and the Sun.
C.
There is a greater gravitational force between Jupiter and the Sun than between Saturn and the Sun.
D. There is a greater gravitational force between Saturn and the Sun than between Jupiter and the Sun.
When you pull the wagon forward suddenly, the ball will
A.
hit the front wall.
B.
hit the back wall.
C.
y up in the air.
D. stay where it is.
Two teams are playing tug-of-war with a rope that has a knot in the middle, as shown below.
When they pull with equal but opposite force, the knot is at rest. However, if the blue team pulls with a
force of 2200 N and the green team pulls with a force of 2500 N, what is the magnitude and direction of
the net (unbalanced) force?
A.
300 N to the left
B.
300 N to the right
C.
4700 N to the left
D. 4700 N to the right
Kara pushes her big brother on a swing at the playground. After he gets o the swing, her little brother
gets on. Kara nds that it is easier to push her little brother than it was to push her big brother. What
is the most likely reason for this?
A.
A smaller mass always moves faster than a larger mass.
B.
A smaller mass always moves slower than a larger mass.
C.
Less force is needed to move a larger mass the same distance.
D. More force is needed to move a larger mass the same distance.
How do Newton's laws help scientists understand more about the physical world?
A.
Scientists can now improve the scienti c method.
B.
Scientists use these laws to study electricity and magnetism.
C.
Scientists can now study concepts without having to make measurements.
D. Scientists use these laws to make predictions about the motion of objects.
Which equation expresses Newton's second law of motion?
A.
F = ma
B.
F=
m
a
C.
F=m
a
D. F = m + a
Which situation is an example of Newton's third law of motion?
A.
A ball in a vacuum container moves in a straight line at a constant velocity.
B.
A ball in a vacuum container accelerates when kicked with a great amount of force.
C.
A person riding in a forward-moving car continues to move forward when the car stops suddenly.
D. A person in a canoe moves the paddle backward in the water, and the canoe moves forward in the
water.
An object's velocity vs. time graph is shown below.
During which interval is there no net force acting on the object?
A.
I
B.
II
C.
III
D. IV
The physical laws discovered by Issac Newton appear to apply
A.
only on the Earth's surface.
B.
only in our Solar System.
C.
most of the time.
D. always and everywhere in the Universe.