magnets
Which combination of magnetic poles will repel each other?
north and north and south and south
Which simple machine is a wheel with a rope or chain around it?
Pulleys
If a light source is at the focal point of a concave mirror
it can make a beam of light
Power plants use generators to produce
electric current
A TV remote control is a source of __________ waves.
infrared radiation
A coil of current carrying wire that produces a magnetic field is called
Solenoid
is made of two inclined planes placed back to back.
wedge
Light rays from a distant object converge after passing through the lens and meet at one point called
focal point
For an object to remain at rest, which of the following must be true?
The forces on it are balanced.
How close or far the wave is called the
amplitude
Why is iron easy to magnetize when used in an electromagnet?
ferromagnetic
The fixed point that a lever rotates around is called the
fulcrum
The mirrors that can make real images are
concave mirror
The human eye changes focus from near to far via
ciliary muscles change the lens
What is the lowest part of the wave?
trough
An iron bar is placed in a solenoid to
increase the magnetic field strength
Screws with threads that are close together have a greater?
ideal mechanical advantage
Objects closer than the focal point of a concave mirror
make a magnified virtual image
Why is it easier to float in salt water than fresh water?
density
What is the highest part of the wave?
crest
What part of an atom is responsible for producing magnetic fields?
electron
the distance along the incline plane divided by its change in height is called the
ideal mechanical advantage
Which is a reason a concave lens can not form a real image
rays diverge
Pressure is
force divided by area
Sound waves can pass through what types of material?
solids, liquids and gases