Potential Energy
What is potential energy?
the energy stored in an object because if it's position (not moving, stretching, high up)
What is kinetic energy?
the energy an object has because it is moving
An object at rest will stay at rest unless acted upon by...
an unbalanced force
a force
north + north
will these magnets attract or repel?
repel
Do gravitational fields attract or repel?
attract
On a rollercoaster, where is potential energy the greatest?
at the highest point of the rollercoaster
Which objects have kinetic energy:
-parked car
-flying bird
-rolling ball
flying bird and rolling ball
because both are moving
What is the name of the scientist who discovered the laws of motion and the law of gravity. (Hint: the unit of measure for force is named after this scientist).
-Isaac Newton
-Newton
The area surrounding a magnet in which the effect of magnetism is felt is called a ________ _________.
magnetic field
As mass increases, the gravitational strength ____________.
increases
(objects with more mass have a stronger gravitational pull)
What 2 factors affect the amount potential energy in a system?
mass and height
What 2 factors affect the amount of kinetic energy in a system?
mass and speed
What does the F, m, and a stand for in the formula F=ma
-force
-mass
-acceleration
What are 2 ways that you can make an electromagnet stronger?
-Use a stronger battery (increase the electric current, more voltage)
-Wrap more coils of wire
-use a larger core (ex: larger iron nail)
As distance increases, the gravitational strength __________.
decreases
(the more distance between an object = the weaker the force of gravity between them)
what is energy transfer?
when energy moves from one object to another
What is the law of energy conservation?
energy cannot be created nor destroyed
Newton's 3rd law:
Every action has an ________ & __________ reaction.
equal & opposite
Where is the magnetic force stronger?
closer to the magnet
What would happen if the Earth didn't have gravity?
What happens to potential energy when an object starts to move?
It converts to kinetic energy
Explain how a car's kinetic energy changes when it speeds up or slows down.
When it speeds up it has more KE
When it slows down it has less KE
What is the name of the force that the floor exerts on a box that is sliding across the floor?
friction
Which set of magnets have more potential energy?
A
since like poles are together, the closer magnets have more PE
Which object has a stronger gravitational pull: the Earth or the moon?
Earth
because it has more mass