Physics Final Exam Review
Terms in this set (74)
inertia in motion; an object in motion wants to stay in motion in a straight line
What does momentum depend on?
mass and velocity
How is momentum related mass and velocity?
directly to both
Which has a greater mass- a heavy truck at rest or a a rolling skateboard? Which has greater momentum?
heavy truck; rolling skateboard
Is momentum always constant?
yes, if velocity is constant
What would make an object's momentum change?
if an object accelerates
when a force is applied to an object over a period of time, resulting in a change in the object's momentum
What are the units for impulse?
What does the amount of impulse depend on?
force and time
When the force of impact on an object is extended in time, does the impulse increase or decrease?
an impulse will cause a change in an object's momentum
Impulse Momentum Theory
Which of Newton's laws is used to prove the Impulse Momentum Theory?
Newton's 1st Law
Newton's 1st Law
an object in motion will stay in motion unless acted upon by an outside force
Does impulse equal momentum or change in momentum?
change in momentum
How can you have the same impulse on two objects with different amounts of force?
the velocities are different
What does it mean to be conserved?
you can't get rid of it
When will an object's momentum be conserved?
when there's no friction
When will an object's momentum not be conserved?
when there is friction
when two objects hit and bounce off of each other
formula for an elastic collision
two objects before, they hit, then they stick together and move as one
formula for an inelastic collision
formula for an explosion
objects stuck together and explode apart
What is another name for an explosion?
a recoil collision
done when a force causes an object to be displaced
What are the units for work?
How can you tell if work is being done?
if something is moving
How must the two requirements for work be acting? (*****parallel or perpendicular)
When will work be positive?
when force and displacement are in the same direction
When will work be negative?
when force and displacement are in opposite directions
What happens when there is no displacement?
no work is done
the rate at which work is done
What are the units for power?
What are two other units that power can be measured in?
horsepower and ___________________________________________
How is power related to work?
How can you increase the amount of power?
use a machine???????????????????????????????
devices that make work easier by changing the magnitude and/or direction of your force
Why do we use machines?
to make work easier
Do machines change the amount of work we have to do?
What do we call the work a person does on the machine?
What do we call the work the machine does for us?
What are the six simple machines?
inclined plane, wedge, lever, wheel and axle, screw, and pulley
What is an ideal machine?
a machine where no work is lost (all the work you put in, you get out)
Compare work in and work out of an ideal machine
they are equal (all the work you put in, you get out)
Compare work in and work out in an actual (real) machine.
work in>work out
Why is work in>work out in an actual machine?
some work is used to overcome friction within a machine
What causes the difference between ideal and real machines?
a ratio of how much a machine increases the effort force
What is meant by the mechanical advantage?
What are the two types of mechanical advantage?
actual mechanical advantage (AMA) and ideal mechanical advantage (IMA)
What are the units for each type of mechanical advantage?
there are no units
What does the efficiency tell us about a machine?
how close it comes to being ideal
how close a machine comes to being ideal
What can mechanical energy be converted into? (formula?)
What are the three particles in an atom?
neutrons, electrons, and protons
Where are neutrons located in an atom?
Where are electrons located in an atom?
outside the nucleus
Where are protons located in an atom?
a device that detects the presence of electric charge
a material that transfers electrons easily
materials that don't transfer electrons easily
Examples of a conductor
Examples of an insulator
What are the three methods of charging?
conduction, induction, and polarization
charging by contact
charging an object by grounding it
the redistribution of charge within a group of particles that produces an apparent charge on the surface of an object
Which method of charging involves contact?
Which method of charging involves grounding?
when an object is connected to the earth by a wire, pipe, etc. so that electrons can transfer to and from the earth
Why do we want to connect a charged object to the earth?
because the earth is so large that we say it can accept or donate an unlimited amount of electrons
What is the only particle that can be transferrers when charging an object?
What are the units for energy?
periodic motion of regular oscillations
Simple Harmonic Motion (SHM)