Motion
what two things must you know to calculate?
Total distance divided by time
What is the SI unit of force?
Newton (N)
What type of force oppeses motion, causing moving objects to slow down and/or stop?
Friction
what is gravity
Force of attraction between objects
what is the difference between speed and velocity?
Velocity has a direction speed is distance travled over time
What is a force?
A push or pull
Describe two ways friction can be reduced.
1, Apply lubricant
2. smooth surface
what two things affect gravity?
1. mass
2. distance
Why is it more helpful to know a tornados velocity rather than its speed?
Velocity tells direction, allowing people to get out of danger and move in a safe direction.
Clay and Tyler were helping a friend move on a couch. Clay pushed the couch with 25 N east. clays little sister pushed back at 10 N west. Calculate the net force.
30 N east
The force of friction exerted by a surface depends on:
The smoothness of the surface
What is the law of universal gravitation
1. larger mass=more gravity
2. greater distance=less gravity
Emily can skateboard 120 meters in 8 seconds. What is her average speed?
15 m/s
What may happen when an object receives unbalanced forces?
It may move
Draw arrows to show the forces action on the wagon.
10kg
What is unit for SI unit for mass?
kilagram (KG)
A kangaroo hops 60 meters to the east in 5 seconds. What is the kangaroos velocity.
12 m/s east
Describe three different ways you can accelerate when riding your bike.
1. Slow down
2. speed up
3. change direction
what force is shown?
applied force
Describe two differences between weight and mass.
1. weight is force of gravity on an object
2. mass Never changes.