A | B |
What is weight? | measure of the force due to gravity acting on a mass |
______ is done when an object is moved through a distance in the direction of the applied force. | Work |
A device that makes work easier is a: | Simple machine |
What are the different purposes of simple machines? | To change the effort needed (mechanical advantage; to change the direction or distance to which the force is applied; to change the speed at which the resistance moves; or a combination of these. |
The work put into a machine is always greater than the work output due to: | friction |
The ratio of workout put to work input is called: | efficiency |
Formula for speed | speed+distance/time (s=d/t) |
Force | Force=mass x acceleration (F=ma) |
Work | Work = force x distance (W=Fd) |
Power | Power = work/time ((P=Wt) |
What is Newton's First Law of Motion? | An object in motion tends to stay in motion, and an object at rest tends to stay at rest, unless the object is acted upon by an outside force. |
What is Newton's Second Law of Motion? | Accerleration=Force/Mass; Force= Mass X Acceleration; A=F/M or F=MA. |
What is Newton's Third Law of Motion? | Every action has an equal and opposite reaction. |
A property of matter that affects the flow of electricity is _____. | resistance. |
Some substances have more ____ than others. | resistance |
____ can cause electrons to be transferred from one object to another. | Friction |
Electricity is related to: | magnetism |
Magnetic fields can produce ___________ in conductors | electrical current |
Electricity can produce a magnetic field and cause iron and steel objects to act like ___. | magnets |
Electromagnets are ____ magnets. | temporary |
Electromagnets lose their magnetism when the _______ is removed. | electric current |
A generator is a device that converts: | mechanical energy into electrical energy |
Most of the electricity we use comes from: | generators |
Electric motors convert: | electrical energy into mechanical energy that is use o do work |
If one burned-out bulb on a string of holiday lights causes the whole string to go out, the lights are on a ____ circuit. If all of the other lights remain lit, the lights are on a ______ . | series; parallel |
Both a motor and a generator have __________ and a coil of wire that creates another magnetic field. | magnets (or electromagnets) |