Identity Crisis
What is Newton's 1st Law?
An object in motion remains in motion and an object at rest remains at rest unless acted upon by an outside force.
Which is easier to move, an object with a high mass or the object with a less mass?
An object with less mass is easier to move
True or False, Unbalanced forces do not change an object's motion
**To receive credit you need explain your answer.
False, balanced forces do not change an object's momentum
If the net force acting on a moving object is zero, the object will _______
Continue in the same direction with no change of speed
Which of the following represent the acceleration due to gravity on earth?
a.) 9.8m/s^2
b.) the variable g
c.) a downward acceleration
d.) all of the above
d.) All of the above!
What is Newton's 2nd Law?
Force is equal to mass times acceleration
F = ma
Which of Newton's laws is often called the law of inertia?
Newton's 2nd Law
True or False, the amount of matter an object has is called it's mass.
*Need an explanation for points
True, mass is a measurement of the amount of matter in an object
The rate of change in the speed of an object is known as _____________
Acceleration
When the only force acting on a falling object is gravity, the object is said to be _________.
In free fall
What is Newton's 3rd Law
For every action there is an equal and opposite reaction
As a skateboarder increases her speed (or velocity) from 2 m/s to 4 m/s, she also increases her ___________.
Momentum
True of False, motion is a measurement relative to a frame of reference
*needs an explanation
True, Motion is measured relative to a situation such as the earth, riding in a vehicle, or some other frame of reference.
_________ is the metric unit of force that is preferred by scientists.
Newton
Air resistance is a type of __________.
a.) motion
b.) acceleration
c.) Velocity
d.) friction
d. friction
The equation that correctly expresses Newton's second law is what?
F = ma
What happens when two forces act in the same direction?
The forces add together
True or false, an example of rolling friction is when bike tires roll across the pavement as you ride on it.
*Must explain why
True! The bike tires roll across the pavement, thus creating rolling friction
Terminal velocity occurs when __________.
the force of gravity is balanced by the air resistance of an object
What is the formula for speed?
Speed = (Distance)/(Time)
The tendency of an object to resist change in its motion is known as what?
Inertia
The force that one surface exerts on another when the two rub together is called ___________
Friction
True or False, Throwing sand on an icy driveway will decrease the friction.
False! This will increase the friction and make it easier for the tires to stick.
The force of gravity on a person of object on the surface of a planet is called ________
Weight
If speed is measured in kilometers per hour and time is measured in hours, the unit for acceleration is what?
Kilometers per hour per hour
or
(Km)/(hr^2
In physical science, what is a push or pull called?
A force
The law of universal gravitation states that any two objects in the universe, without exception __________
attract each other
True or False, A person in a car that stops suddenly will keep moving forward (without a seatbelt) due to friction.
False! They will continue moving forward (without a seatbelt) due to inertia
According to Newton's third law of motion, when a hammer strikes and exerts force on a nail, the nail __________.
Exerts an equal force back on the hammer
If the speed of an object does NOT change, the object is traveling at a ___________
Constant Speed
What is the term to describe the overall force on an object after all the forces are added together?
The motion of an object will continue in the same direction at the same speed unless acted upon by _____________
a force
True or False, Friction acts in the same direction to an object's motion.
*Need an explanation
False! Friction acts in the opposite direction of an object's movement.
When you know both the objects speed and direction then you know what?
It's Velocity
The statement that the motion of a hurricane is 20 km/hr east is a description of the hurricane's __________.
Velocity