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