the density of free electron in a copper conductor is 8.5×10^28m-3. how long does an electron take to dift from one end of a wire 3.0m long to it's other end?

Which material produces static charge when rubbed?

Heena wants to measure the volume of a ball that is 24 cm across. how should she set up her equation?

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?