Kepler-186f is an exoplanet that orbits a star other than the Sun. Its star is the red dwarf Kepler-186. It is the first planet to be discovered that orbits its star at a distance like Earth’s distance from the Sun. If Kepler-186f is approximately 5.4 x 1010 meters from Kepler-186, how long does it take for light from the star to reach the exoplanet? The speed of light is 3.0 x 108 m/s. It takes 3 minutes

The density of a liquid could be found by using

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)

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