Motion
What two things must you know to calculate speed?
total distance divided by total time.
What is the SI unit of force?
Newton (N)
What is gravity?
Force of attraction between objects.
What type of force OPPOSES motion, causing moving objects to slow down and/or stop?
Friction
What the difference between speed and velocity?
Velocity has a direction. Speed is distance traveled over time.
What is a force?
A push or a pull.
what two things affect gravity?
1. Mass 2. Distance
Describe two ways friction can be reduced.
1. Apply lubricant 2. Smooth surface
Why is it more important to know a tornado's velocity rather than it's speed?
Velocity tells direction and speed, allowing people to get to move to a safe direction and out of danger.
Clay and Tyler were helping a friend move a couch. Clay pushed with 25 N east and Tyler pushed with 15 N east. Clay's little sister pushed back with 10 N west. What is the net force?
30 N east
What is the Law of Universal Gravitation?
1. Larger mass = more gravity
2.Greater distance = less gravity
the force of friction exerted by a surface depends on:
The smoothness of the surface.
Emily can skateboard 120 meters in 8 seconds what is her average speed?
15 m/s
What may happen when an object receives an unbalanced forces?
It may move.
What is the SI unit for mass?
kilogram (kg)
what are the two forces that keep a book on a table?
Gravity and Normal force