Julian designs an experiment to see how well different liquids lubricate wooden surfaces. he sets up a number of identical wooden ramps and prepares to slide identical wooden blocks down them. he will time how long it takes each block to reach the end of the ramp. he covers one ramp with water, the second with motor oil, and the third with corn syrup.

what can julian use as a control group for the experiment?

a.
a block that drops straight down instead of sliding down a ramp
b.
a ramp with no liquid on it
c.
a second set of ramps covered with water, oil, and syrup respectively
d.
a ramp with no friction on its surface
reset submit

the answer is B.

Explanation:

This is because the experiment is done to see how well liquids lubricate compared to non - lubricated surfaces. in this experiment the non - lubricated surface is the wooden ramp so it should be used as control experiment.

the word that best describes martin luther king jr.'s tone in the video is dignified

martin luther king, jr. was a social activist and baptist minister who played a key role in the american civil rights movement from the mid-1950s until his assassination in 1968. the video shows his manner and attitude having or showing a composed or serious manner that is worthy of respect so dignified is the correct answer

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia