Which of the following statements is a consequence of the equation e = mc2?
a
energy is released when matter is destroyed.
b
mass and energy are equivalent.
c
the law of conservation of energy must be modified to state that mass and energy are conserved in any process.
d
all 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.)

The frequency of a tuning fork can be found by the method shown. a long tube open at both ends is submerged in a beaker of water, and the vibrating tuning fork is placed near the top of the tube. the length l of the air column is adjusted by moving the tube vertically. the sound waves generated by the fork are reinforced when the length of the air column corresponds to one of the resonant frequencies of the tube. the smallest value for l for which a peak occurs in sound intensity is 7 cm. l what is the frequency of the tuning fork? the speed of sound in air is 345 m/s. answer in units of hz

Aproper cool-down routine does which of the following? a). motivates you for your next workout b). the body adjust back to a resting state c). leaves you feeling worn-out d). strengthens muscles