An object is moving under a constant acceleration (never changes at any point). it is initially moving in the +x direction at 7 m/s. after some time the object stops and then starts moving in the -x direction. after a total time of 9 seconds, its average velocity for the entire trip is 8 m/s in the -x direction. how much distance does the object cover in this time in meters?

Aperson walking 1 mile everyday for exercise, leaving her front porch at 9: 00 am and returning to her front porch at 9: 25 am. what is the total displacement of her daily walk? a) 1 mileb) 0c) 25 minutes d) none of the above

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)

Contains chemical energy. a. heat b. light c. natural gas