20 points and brainliest if your answer is correct!

you are designing an experiment to test the efficiency of different bikes. what simple machines to make this complex machine?

a. wedge, pulley, and wheel and axle

b. wedge, screw and wheel and axle

c. screw, inclined plane and wheel and axle

d. screw, lever, and wheel and axle

Astudent is performing an experiment comparing sound and light waves. the student gathers the following data. what conclusion does the student most likely make based on this data? light waves always travel the same speed; however, the speed of sound is determined by the medium that it travels through. all sound waves always have the same energy, so the temperature of the medium does not affect wave speed. light needs to vibrate particles, so it travels fastest in tightly packed solids, while sound does not need a medium, so it travels fastest in a gas. tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

Aphysical change is a change in the size, shape,, or stafe of matter true or false

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared