Which answer accurately describes the difference between speed and velocity? question 8 options:
a. speed can be constant or it can change. velocity is always constant.
b. speed requires direction. direction doesn't matter when calculating velocity.
c. speed is the distance per unit of time. velocity is the displacement per unit of time.
d. speed is the same as average velocity. velocity is used to calculate acceleration.

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

A3.9 g aluminum foil ball with a charge of +4.1×10−9 c is suspended on a string in a uniform horizontal e⃗ field. the string deviates to the right and makes an angle of 30∘ with the vertical. part a part complete what information about the e⃗ field can you determine for this situation? what information about the field can you determine for this situation? only the magnitude of e⃗ only the direction of e⃗ both the magnitude and the direction of e⃗ none of the above previous answers correct part b determine the magnitude of the electric field. express your answer with the appropriate units. e e = nothing nothing request answer part c determine the direction of the electric field. determine the direction of the electric field. to the right to the left away from you toward you

We have a colorless transparent liquid. it looks like water. we seperated it into a solid and a liquid by evaporration and condention was this a chemichal or a physical seperation a. chemical seperation b. physical seperation