Vocab
What is the definition of a force?
A. a form of potential energy
B. a push or pull on an object
C. an electrical or magnetic field
D. an object that is moving or changing shape
A push or a pull exerted on an object
Which of these are a contact force
A. gravity
B. friction
C. air resistance
D. magnetic force
E. pushing with your hands
Friction
Pushing with your hands
Which of these is an example of the transformation of kinetic energy into gravitational potential energy?
A. a person walking up a hill
B. a person skiing down a hill
C. a car racing around an oval track
D. a person parachuting out of an airplane
B. a person skiing down a hill
True or false:
The mass of an object effect it's motion
True
Finish the sentence:
Newton's first law say's an object at rest will remain at rest unless acted on by ____________
an outside force
What does a Newton measure?
Force
What type of energy does potential energy turn into when an object is in motion
Kinetic Energy
What type of energy does a falling ball have?
Gravitational potential energy
True or false:
Not all forces have strength.
False
If two equal forces are acting on an object, the object will?
A. Move to the right
B. Move to the unbalanced side
C. Remain in place
D. Break
C. Remain in place
What is a reference point?
a location to which another location is compared
What force could cause an apple hanging from a tree branch to fall?
Gravity
True or false:
If two unbalance forces act on an object, the object will move to the side with greater force
True
Why are some forces considered to be noncontact forces?
A. Objects must be far apart in order to exert a force.
B. Objects do not have to touch each other to experience a force.
C. Objects must be large in size in order to exert a force that is strong enough to notice.
D. Objects must be large in size in order to exert a force that is strong enough to notice.
A soccer player kicks a ball. On what to objects is force being exerted?
The soccer player's foot and the ball
What is the difference between kinetic energy and potential energy?
kinetic energy (kih•NET•ik EN•er•jee)
the energy of an object that is due to the object's motion
potential energy (puh•TEN•shuhl EN•er•jee)
the energy that an object has because of the position, condition, or chemical composition of the object
Jose throws a baseball into the air. It rises, stops when it reaches its greatest height, and then falls back to the ground. At what point does kinetic energy convert to potential energy?
When the baseball reaches the greatest height and begins to fall
How are speed and velocity related to each other?
A. Speed and velocity are the same thing
B. Velocity and speed both include direction and a change in position over time
C. Speed is a change in position over time, velocity is both direction and a change in position over time
D. Speed needs direction, velocity is just a change in position over time
C. Speed is a change in position over time, velocity is both direction and a change in position over time
What two things are important to know when calculating the net force of an object?
A. Direction and force
B. Force and speed
C. Acceleration and speed
D. Direction and gravity
A. Direction and force
What is the equation from Newton's second law?
Force = mass x acceleration
Which statement best describes the relationship between velocity and acceleration?
A. Velocity is the rate of change in acceleration.
B. Acceleration is the rate of change in velocity.
C. Velocity and acceleration are not related to each other.
D. Acceleration can only be a positive value regardless of the velocity.
B. Acceleration is the rate of change in velocity.
When scientists studied geological columns from different parts of the world, they discovered something interesting: the fossils of dinosaurs and many groups of reptiles and marine invertebrates disappeared at the top of the Mesozoic section. What is the most likely explanation of this evidence?
An extinction event caused many of the organisms to die off.
What change would increase the kinetic energy of a moving object the most?
A. reducing the mass by half
B. reducing the speed by half
C. doubling the mass of the object
D. doubling the speed of the object
A. reducing the mass by half
D. doubling the speed of the object
A box has two forces acting on it. One force is 100 N upward. Another force is 50 N downward. What is the net force on the box?
A. 50 N upward
B. 100 N upward
C. 50 N downward
D. 100 N downward
A. 50 N upward
Carts A and B each have the same force applied to them. Cart A has half the mass of Cart B. How does Newton’s first law of motion predict the resulting accelerations of the carts?
A. Cart A will have the greater acceleration.
B. Cart B will have the greater acceleration.
C. Carts A and B will have the same acceleration.
A. Cart A will have the greater acceleration.