An astronaut leaves the International Space Station (ISS) on a tethered line. Although ISS and Earth exert gravitational force on the astronaut, why does she appear to be weightless?
A) Earth only exerts gravitational force on objects at its surface.
B) The mass of the astronaut is insufficient to be affected by gravity.
C) Earth and ISS cancel each other's gravitational force on the astronaut.
D) The distance from Earth and mass of ISS exert negligible gravitational force on the astronaut.

Nacidified solution was electrolyzed using copper electrodes. a constant current of 1.18 a caused the anode to lose 0.584 g after 1.52 ✕ 103 s. given that the charge of an electron is 1.6022 ✕ 10−19 c, calculate avogadro's number. assume that copper is oxidized to cu2+ ions.

What kind of simple machine is a catapult?

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