Forces & Motion
True of False?
Gravity is a force that pushes objects toward the center of the earth.
Give 2 examples of potential energy we can see in the classroom.
any acceptable answers
"The ability to do work" is the definition of this vocabulary word.
Energy
________________ surfaces have ______ friction than rough surfaces.
Smooth; less
Any push or pull
Force
Running is an example of _________ energy.
kinetic
When 2 or more objects rub against each other, this force is present.
friction
Objects with _________weight (or mass) have a __________ gravitational pull.
more; stronger
Give 2 different examples of a pull.
any acceptable answers
When an object with potential energy begins to move, what happens to that potential energy?
It turns into kinetic energy.
Give an example of a sport when you DO NOT want much friction.
I will judge acceptable answers.
As a bicycle goes up a hill, what type of energy is DECREASING?
kinetic
When forces are balanced, do objects change direction or speed, or do they remain still?
They remain still.
Explain the difference between kinetic energy and potential energy.
Kinetic - energy of motion
Potential - energy stored in an object
Is it easier to stop a normal-sized car or an 18-wheeler semi truck?
Why?
The semi truck is harder to stop because it has more mass/weight.
Give an example of balanced forces.
You CANNOT use arm wrestling as an example.
Balanced - forces that act on an object WITHOUT changing its motion
Unbalanced - forces that change the motion of an object
I'll accept any reasonable answers.
In arm wrestling, how do you know when forces are unbalanced?
When their arms move.
How can you give an object more potential energy?
Place it up higher.
In a game of marbles, how do the marbles in the circle get the energy to move?
Energy is transferred from the shooter marble to the other marbles.
If you transfer your energy into a bowling ball, then the bowling ball hits the pins, what happens to the energy in the bowling ball?
It is transferred to the pins.