Force Concepts
What is force?
A push or pull that can change the motion of an object
What is the difference between speed and velocity?
Velocity has a direction
A water bottle is motionless on a desk. Are the forces balances? What is the net force?
The forces are balanced, the net force is 0.
A magician quickly pulls a tablecloth out from under a set of dishes. The dishes remain in the same spot.
Newton's 1st Law
Which object has more inertia? A pen or a bowling ball?
A bowling ball, because it has a greater mass.
What is Mass?
The amount of matter in an object
What is acceleration?
How fast something speeds up, or slows down.
Are the forces in this video balanced or unbalanced?
There is no change in speed or direction, so the forces are balanced
What law is also called the Law of Inertia? What is Inertia?
Newton's 1st law. Inertia is the tendency for objects to resist changes in motion.
A full shopping cart requires more force to push than an empty shopping cart
Newton's 2nd Law of Motion
If I kicked a soccer ball along the grass, would it keep moving forever? Why or why not?
The soccer ball would eventually stop due to friction.
A car is driving 35 mph. Is this an example of speed, velocity or acceleration?
It is an example of speed. It is not velocity because there is no mention of direction and it is not acceleration because the speed is not changing.
In the video, when are forces balances? When are they unbalances?
They are balanced when the cloth is above the pool, and unbalanced when the boy falls into the pool
A force of 10 N is exerted on a ball, causing it to roll to the right. How can we slow this ball down? Will the force be greater, equal to or less than 10 N?
To slow the ball down, we need to exert a force in the opposite direction the ball is moving. The force will be less than 10 N.
In this video when are forced unbalanced? When are they balanced?
They are unbalanced when the force of gravity is larger than air drag. They are balanced when the force of gravity is equal to air drag.