Need asap !
which of the following is an example of work being done on an object?
a.
a man pushes a couch across the room.
b.
a prism scatters ultraviolet light into visible light.
c.
a box rests on the floor.
d.
water in a pot changes into steam.

in the diagram above, which letter identifies an axle?
a.
x
b.
z
c.
y
d.
w

which simple machine can be described as a shaft that is attached to the center of a wheel?
a.
lever
b.
inclined plane
c.
pulley
d.
wheel and axle

usually, levers are used to reduce the input force needed to move an object. this is only possible when the input force acts over a long distance and the object moves a shorter distance.

however, sometimes levers are designed to increase the input force needed to move an object. which of the following is most likely an example of this type of lever?
a.
a catapult
b.
a see-saw
c.
a wheelbarrow
d.
a crowbar