if a total mass of electrons in 1 mole (6.022*10^23) of atomes of a cerrtain element is 30.17 mg, how many protons must there be in the nucleus of the atom?

Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.

16. a brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 n on him. the mass of the losing player plus equipment is 90.0 kg, and he is accelerating at 1.20m/s2 size 12{1 "." "20"" m/s" rsup { size 8{2} } } {} backward. (a) what is the force of friction between the losing player’s feet and the grass? (b) what force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? (c) draw a sketch of the situation showing the system of interest used to solve each part. for this situation, draw a free-body diagram and write the net force equation.

If water vapor with the mass of 35.0 grams is cooled and condensed into water in a closed system such as a closed glass jar, what is the mass of the water after the water vapor completely condenses? a) 34.5 grams b) 35.0 grams c) 35.5 grams d) the mass cannot be determined without knowing the volume