If the average density of planet x is equal to earth's average density, ρe, what is the ratio of rx/re, where re is the mean radius of earth

Acharge of 8.4x10^-4 c moves at an angle of 35 degrees to a magnetic field that has a field strength of 6.7x10^-3 t. if the magnetic force is 3.5 x10 ^-2 n, how fast is the charge moving?

Iwill give 30 points to whoever answers ! what is the formula for actual mechanical advantage and ideal mechanical advantage?

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration