Physics 1135 Self Test
What is a machine?
A machine is any device that transfers energy from its point of input to its point of use
How is it possible to move a spacecraft through frictionless space?
A spacecraft is able to move through space through the use of an action-reaction engine
What is force?
any influence capable of producing a change in velocity of a body
vibration
back-and-forth motion
List the three examples of potential energy.
firewood, steam under pressure, dynamite, stored electricity, gravitational potential energy
When the fulcrum is between the load and the effort, the lever is ...
first class
The period of pendulum is dependent on its ...
length
List the six simple machines.
lever, inclined plane, wheel and axle, pulley, wedge, screw
Momentum is the product of what two quantities?
mass, velocity
amplitude
maximum displacement
simple harmonic
motion of a pendulum
work
product of a force and distance
frequency
reciprocal of the period
When the load is between the fulcrum and the effort, the lever is ...
second class
When the effort is applied between the load and the fulcrum, the lever is ...
third class
period
time it takes to make a complete swing
List two purposes for which machines can be used.
to change direction of the effort, to multiply the effort, to change the distance through which the effort acts
hertz
unit equal to one cycle per second
State the law of conservation of energy.
Energy can neither be created nor destroyed, but only changed from one form to another
... is equivalent to momentum and has the same units
Impulse
Define kinetic energy.
Kinetic energy is the ability to do work because of a body's motion
What is mechanical advantage?
Mechanical advantage is the ratio of load to effort
What is power?
Power is the measure of the speed at which work is done
Explain how efficiency is calculated.
The efficiency is the work output divided by the work input and written as a percent
State the law of conservation of momentum.
The total momentum before an impact equals the total momentum after the impact
Explain why theoretical advantage is not equal to actual mechanical advantage.
The two are never equivalent, because some of its energy is lost, usually due to friction
Define work.
Work is the product of force and distance through which force is applied
List the two of three types to remember when using the law of conservation of energy.
a particular type of energy may not be conserved, almost all energy changes result in an increase in the amount of heat energy at the expense of other types of energy, the law of conservation of energy is not true under all circumstances
List the two types of simple harmonic motion used in clocks to keep time
a swinging pendulum, hairspray winding and unwinding, the vibrations of a quartz crystal