Friction moves in the _____________ direction to a moving object.
opposite
100
If two people are pushing a box in the same direction, and one is pushing with 5N of force and the other is pushing with 10N of force, what is the total net force?
15N
100
Something we change in an experiment is called a...
variable
200
This is the unit we use to measure force.
Newtons
200
The rate of an increase or decrease in speed is...
acceleration
200
Which surface would have more friction: a mirror or a brick wall?
A brick wall
200
If two people are pushing a box on opposite sides, and one person is pushing with 15N of force and the other person is pushing with 10N of force, what is the total net force?
5N
200
This is a force caused by air to slow things down (much like friction).
Air resistance
300
What do the letters in the formula F=ma stand for?
Force, mass, and acceleration
300
Describe the difference between kinetic energy and potential energy.
Kinetic energy is the energy of motion.
Potential energy is stored energy.
300
What allows maglev trains to move so quickly?
They don't touch ground or tracks, so they run on frictionless surfaces.
300
What is the amount of force needed to push a 5kg stone 5m/s2?
25N
300
What does SPQ3R stand for?
Survey, predict, questions, read, respond, review
400
Why would you weigh more on Jupiter?
Jupiter is larger and has a greater gravitational pull on us, making us weigh more. (Remember, weight is the measure of gravitation pull on us.)
400
Which would accelerate faster: an elephant or a mouse? Why?
The mouse would accelerate faster because it has less mass. The elephant has more mass, so it would take longer to accelerate.
400
The doorstop in Mrs. Fried's door doesn't have enough friction to hold the door open, so it keeps sliding. What could she do to it to give it friction?
Add rubber (or anything with grip) to the bottom, scratch the surface of the doorstop to make it rougher, etc.
400
What is the amount of force needed to pull a 30kg walrus 4m/s2?
120N
400
What variable did we change when we worked with the tracks and toy cars?
We changed the amount of friction the car experienced each time (rolling on tires, sliding on roof, rolling on paper towels).
500
What does Newton's Second Law of Motion tell us?
The greater the mass of the object, the more force you will need to make it move, and the smaller the mass of the object, the less force you will need to make it move.
500
Which would have more kinetic energy: an elephant or a mouse? Why?
(Hint: Both animals are moving at the same speed.)
The elephant would have more kinetic energy because it has more mass.
500
What do we call the measure of the amount of friction between two surfaces?
(Hint: Ice and rubber would have a lower one than concrete and rubber.)
Coefficient of friction
500
If you use 100N of force to push a dog 20m/s2, what is the mass of the dog?
5kg
500
What is the average speed of a car traveling 246 cm in 4.2 seconds?