What is the medium? what can it be used for.

Any color picture tube and electric field exerts a net force of magnitude 1.68x 10^-13 n on an electron the rest mass of an electron is 9.11 x 10^-13 what is the electron acceleration?

Oxygen and hydrogen gas are at the same temperature t.what is the ratio of kinetic energies of oxygen molecule and hydrogen molecule if oxygen is 16 times heavier than hydrogen.

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?