Ciara is swinging a 0.015 kg ball tied to a string around her head in a flat, horizontal circle. The radius of the circle is 0.70 m. The ball is going 7.33 m/s.
If the speed is tripled, what happens to its centripetal force? (3 points)
a) The new centripetal force is 1/3 what it was
b) The new centripetal force is 3 times more
c) The new centripetal force is 1/9 what it was
d)The new centripetal force is 9 times more

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

Do you agree with scientist’s prediction about the warming of alaska and other polar regions?

Chemical energy is a form of energy. a. heat b. kinetic c. potential d. electromagnetic