Alisa, a skateboarder, is riding down a hill. If Alisa and the skateboard are considered a single object, what forces are acting on her? Check all that apply.

gravity

normal force

friction

Explanation:

A force is refered to as the interaction which when unopposed, will lead to a change in an objects motion. The velocity of an object will be changed when force is applied.

Since Alisa s riding down a hill and she and the skateboard are considered to be a single object, then the forces that are acting on her include gravity, normal force and friction.

the closer the planet is to the sun, the larger the gravity

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form