A wheel has an angular speed of 54 rev/s when it experiences a constant angular acceleration of 64 rev/s2 which causes it to spin FASTER. During this time the wheel completes 81 rev. Determine how long the wheel was experiencing this angular acceleration. Express your answer using appropriate mks units.

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.

15. one purpose of the tread pattern on a tire is to a reduce tire wear. b. reduce traction c. allow water to flow away from the tire. d. look impressive.

This is the substance(s) formed in a chemical reaction.