A roller coaster car is released from a standing start at the top of a 20.0-m hill. The car rolls down the hill to a point 10.0 m above the ground, then up a second hill to 15.0 m, and then down again to point X at 8.00 m above the ground. Use what you know about the sum of the kinetic and potential energies to find the car's speed at X. A.
11.7 m/s
B.
12.5 m/s
C.
15.3 m/s
D.
19.8 m/s

Around faucet handle is part of a(n) a. lever b. screw c. inclined plane d. wheel and axle

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?

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.)