If element X has 78 protons, how many electrons does it have?

1 In which direction does the Sun appear to move across the sky?. from west to east from east to west from north to south from south to north

What size force will open a door of area 1.54m^2 if the net pressure on the door is 1.013 * 10^3 Pa?

A car travels around a racetrack at aconstant speed. During what parts of the coursedoes the car experience acceleration?

A feather of mass 0.001 kg falls from a height of 2 m under realistic conditions it experiences air resistance based on what you know about friction what can you say about the kinetic energy of the feather as it reaches the ground

An 80-kilogram skier slides on waxed skis along a horizontal surface of snow at constant velocity while pushing with his poles. What is the horizontal force pushing him forward?

A solid sphere of radius R has a total charge Q distributed evenly throughout its volume. What fraction of the total charge is located inside a radius R/2?

What is Nothing. (sorry i have been wondering this for a very long time)

What is the speed of a bobsled whose distance-time graph indicates that it traveled 123m in 28s?

Eric has a mass of 80 kgkg. He is standing on a scale in an elevator that is accelerating downward at 1.7 m/s2m/s2. What is the approximate reading on the scale?

Without the force of friction, people would not be able to walk.