Potential or Kinetic
A roller coaster at the top of a hill
potential energy
Energy is never created or destroyed
Law of Conservation of Energy
When you can float easier in saltwater it is because...
It has greater density than fresh water
a force exerted by a person or object onto another object
applied force
A force of attraction or pull between two objects
gravity
A bowling ball rolling toward the pins
kinetic energy
An object at rest will remain at rest and and object in motion will remain in motion unless acted on by unbalanced forces
Newton's 1st Law
When a car suddenly stops and a book sitting on the back seat flies off, it is because the book has ____ and it's momentum keeps it moving even though the car is stopping.
inertia (Newton's 1st Law)
when a spring is compressed or stretched
spring force
a force that opposes motion
friction
The two factors that determine the amount of kinetic energy
mass and speed
For every action there is an equal and opposite reaction (forces come in pairs)
Newton's 3rd law
A box has a 6N force pulling to the left and a 10N force pulling to the right. What is the net force and direction?
4N to the right
the amount of motion an object has
momentum
When an object is immersed in a fluid, the fluid pushes up on the object. This force is called __________
buoyancy
The two factors that determine the amount of potential energy are
height and mass
An object with mass accelerates when a force acts on it. The greater the mass of the object being accelerated, the more force needed to accelerate the object. F= m x a
Newton's 2nd Law
A box weighing 20lbs on Mars (gravity of 3.7 m/s) was then transported to Venus (gravity of 8.9 m/s). What happened to the weight of the box? (increase/decrease/same) What happened to its mass? (increase/decrease/same)
Weight increases
Mass stays the same
the tendency to resist change in motion
inertia
equal and opposite to the force of gravity
normal force
A boulder weighing 2,000 g is rolling down a hill at 20 feet per second. A rock weighing 200 g is also rolling down the same hill at 20 feet per second. Which object has more kinetic energy?
the boulder- because it has more mass
How momentum and inertia are related: If there is more momentum, is there more or less inertia?
More inertia
Using the formula v = d / t
A car travels 60 meters east in 10 seconds. What is the velocity?
6 m/s
forces resulting when two objects do not touch each other, such as with gravity, magnetic force, and electric force
noncontact forces
when two objects pull in opposite directions
tension