Unit 2: Forces and Newton's Laws Flashcards
Describe Force.
A Push or Pull acting on a object.
What is an applied force?
A Force applied to an object by a person or other object.
What forces act on you as you ride a scooter?
Gravity, Friction and applied forces
Gravity is…
Pulls something to the ground
Every time the motion of an object changes, it’s because…?
A force has been applied to it.
Force can cause a stationary object to….
Start moving or a moving object to stop or to simply change its speed or direction or both.
Acceleration means…
A change in speed or direction of an object
The SI unit for force is…
Newton (N)
True or False: Foce is a Vector
True
Reminder: Vector is…
Measure of both size and direction. It can be represented by an arrow. As Force is a vector, force can be represented by an arrow.
What does Friction mean?
Result of motion that opposes motion between any surfaces that are touching.
Why does Friction occur?
No surfaces is perfectly smooth!
What are 2 factors that affect Friction?
- How smooth or rough the surface is
- How heavy an object is (it’s mass)
True or False: Friction can’t produce heat
False. Friction can produce heat. Friction causes the molecules on rubbing surfaces to move faster so they have more energy. This gives them a higher temperature, and they feel warmer.
What is Net Force?
Net Force is defined as the sum of all forces acting on an object.
What is a balanced force?
It has 0 Net force and no change in motion. To sum up, the object isn’t moving.
What are a few examples of balanced force? (The answers will vary.)
- Paper of desk
- You sitting in a chair
- A bowl on a counter
- A flag NOT moving
What is a UNBALANCED force?
There is a Net force on an object that is causing a change in motion.
If you are solving for Net Force and the forces are moving in the same direction, you would need to…
Add the forces.
If you are solving for Net Force and the forces are moving in opposite directions, you would need to…
Subtract the forces.
What are Newton’s laws of motion? (1st and 2nd only)
- An object in motion tends to stay in motion and an object at rest tends to stay at rest unless acted upon by an unbalanced force.
- Force equals mass times acceraltion. (F= MA)
What is Newton’s First Law of Motion?
An object in motion will stay in motion and an object at rest will stay at rest until acted upon by an unbalanced force.
According to Newton’s First Law of Motion, if an object was moving at a constant velocity then it will…
Keep Moving
It takes _________ to change the Motion of an object. Fill in the blank.
Force
Newton’s First Law is also called the…
Law of Inertia
Inertia means…
Tendency of an object that resist changes in it’s state of motion.
What does the First Law state about Inertia and Mass?
All objects have Inertia. Inertia will slow something down. The more mass an object has, the more inertia it has.
According to Newton’s First Law of Motion, is this statement True or False: Balanced Forces are needed to move a pencil across a desk.
False
According to Newton’s First Law of Motion, is this statement True or False: A chair will move by itself because of its inertia.
False
According to Newton’s First Law of Motion, is this statement True or False: Newton’s First Law of Motion describes how inertia affects moving objects.
True
According to Newton’s First Law of Motion, is this statement True or False: In a car accident, a passenger NOT wearing a seatbelt may crash through the windshield because of his or her inertia.
True
According to Newton’s First Law of Motion, is this statement True or False: A balanced force does not change the velocity of an object.
True
According to Newton’s First Law of Motion, is this statement True or False: An object will remain at rest unless a balanced force acts upon it.
False
According to Newton’s First Law of Motion, is this statement True or False: In baseball, inertia makes it easy for a baseball player to make sharp turns at bases?
False
What is Newton’s Second Law of Motion?
Force equals Mass times acceleration (F=MA)
According to Newton’s Second Law of Motion, what 2 things have a direct relationship?
Force and Acceleration
According to Newton’s Second Law of Motion, what 2 things have an Inverse relationship?
Mass and Acceleration
What does Weight mean?
Gravitational force; a measure of how strong gravity pulls on an object.
What does Mass mean?
Amount of matter an object contains
Your ____ depends on the strength of gravity. Fill in the blank
Weight
What is the Formula for finding Force?
F= MA
What is the Formula for Acceleration?
Force/Mass
What is the Formula for Mass?
Force/Acceleration
Do all objects fall at the same rate? (True or False)
(Dropped at same heights and time)
True
What is Newton’s 3rd law of motion?
For every action, there’s always an equal and opposite reaction
Is this an example of Newton’s 3rd law of motion: Balloon contracts the air outwards through the entry in which the balloon moves the opposite direction?
YES
