A skateboarder pushes the ground with one foot, and moves forward. Which statement BEST explains his motion?
The mass of the skateboard decreased causing acceleration to move him forward.
The unbalanced force exerted by the skateboarder’s foot caused him to move forward.
The mass of the student and skateboard increased causing acceleration to move him forward.
The balanced forces on the skateboard allowed it to change his motion and move him forward.

C or D i would think would be the answer

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).

answer: d. a cme increases the amount of energy in the solar wind

explanation:

coronal mass ejections, also called cmes, are large clouds of plasma and magnetic field that erupt from the sun. only when the cloud is aimed at earth will the cme hit earth and therefore cause impacts. high-speed solar wind streams come from areas on the sun known as coronal holes.