Which of the following statements describes a compound machine?
a.
it has movement in only one direction.
b.
it can only be acted on by one force.
c.
it is made up of more than one simple machine.
d.
it makes work more difficult.

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

True or false: the revolution of the earth creates day and night as it rotates around the sun

Which car has the most kinetic energy? a. a car of mass 1000 kg with a speed of 3 m/s b. a car of mass 2000 kg with speed 7 m/s c. a car of mass 1000 kg with speed 7 m/s d. a car of mass 2000 kg with speed 3 m/s