Vocabulary
A group of objects from which a position in motion is measured.
Frame of Reference
A rubbing force that acts against the motion between two touching surfaces and always slows an object down is known as...
Friction
A collection of forces acting on an object that cancel each other out and produce no change in the objects motion
Balanced Forces
What is Newton's First Law of Motion?
An object at rest tends to stay at rest, and an object in constant motion tends to stay in motion, unless acted upon by an unbalanced force.
30 miles per hour south is an example of...
(Hint: you're given speed and direction)
Velocity
How fast an object's position changes over time
Speed
True or False: A smooth slide will have more friction than a bumpy, rough slide.
False
A collection of forces acting on an object that result in a change in the object's motion
Unbalanced Forces
What is Newton's Second Law of Motion?
The unbalanced force on an object is equal to the mass of the object multiplied by its acceleration (F = m x a)
Which of these is an example of force?
A. Pulling brownies out of the oven
B. Watching an egg cook on the stove
C. Listening to the radio in the car
D. Bird Watching
A. Pulling brownies out of the oven
KEY WORD: "pulling"
A change in an object's position over time
Motion
True or False: Friction is a force that tends to slow an object down.
True
I am playing tug-of-war against Mrs. Tran. I am pulling with 10N of force. Mrs. Tran is pulling with 5N of force. Are these forces balanced or unbalanced?
Unbalanced (I am pulling with MORE force than Mrs. Tran, which will cause motion)
According to Newton's First Law of Motion, objects in motion will stay in motion unless acted upon by an external force. What would happen if there were no external forces (i.e. no friction, no drag, no gravity)?
You would continue in motion forever (Think: SPACE!)
Friction will:
A. Speed you up
B. Slow you down
B. Slow you down
The location of an object
Position
Sample Answer (answers may vary):
Helpful - Friction between shoes and the floor help to stop us from slipping.
Harmful - Wear and tear on our shoes due to friction ultimately causes them to fall apart and develop holes.
Students are acting crazy and trying to break into my room in the morning. I am pushing the door closed with 30N of force. The students are pushing against the door with 30N of force. The door will not budge. Are these forces balanced or unbalanced?
Balanced (we are pushing with the same amount of force, so there is no motion!)
What is Newton's Third Law of Motion?
All forces occur in pairs, and these two forces are equal in strength and opposite in direction.
List the "Fantastic Four" ways to change an objects motion.
1. Change an object's speed
2. Make an object move
3. Stop an object
4. Change the direction of an object
The speed and direction of a moving object
Velocity
Provide 3 examples of friction that occur in your everyday life.
Sample Answer (answers may vary):
1. My shoes and the sidewalk
2. My car's wheels and the road
3. My pencil writing in my notebook
The swings outside are pulled by both the chain on the swing as well as the earth's gravity. Due to this, the swing does fly into the sky or drop on the ground. Does this mean the forces are balanced or unbalanced?
Balanced
How do air resistance, drag, and friction relate to Newton's First Law of Motion?
Newton's First Law states that an object in motion tends to stay in motion unless acted upon by an external force. Air resistance, drag, and friction are those external forces.
Why is velocity more important than speed when traveling?
You need to know BOTH the speed to get to your destination as well as the direction in which to go to arrive at your destination.