Two small spheres spaced 20.0 cm apart have equal charge. How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57 x 10-21 N?

A. 562

B. 9.14 * 10^3

C. 1.01 * 10^6

D. 891

How is work defined in physics

A fisherman casts his bait toward the river at an angle of 25° above the horizontal. As the line unravels, he notices that the bait and hook reach a maximum height of 2.9 m.

Technician A says that distilled or clean drinking water should be added to a battery when the electrolyte level is low. Technician B says that fresh electrolyte (solution of acid water) should be added. Which technician is correct? A.

You serve a volleyball with a mass of 2.1 kg. The ball leaves your hand with a speed of 30 m/s. The ball has what energy, kinetic or potential

1. Which of the following is a true statement concerning the electrostatic force and gravitational force acting on an electron and a proton in an atom? Fg > Fel Fel > Fg Fg = Fel We would need to know which atom 2.

A train is slowing down with an average acceleration of - 5.0 m/s2 (negative sign shows deceleration). If its initial velocity is 50. m/s, how far does it travel in 6.0 seconds?

3. Infer A car is travelling down a straight road. The driver presses on accelerator but the car does not ch speed. How is this possible? esses on the oes not change

What is located in the exosphere?

How fast should a 250g mouse run so that it can have the same momentum as a 3ton (1metric ton = 1000kg 1g=0.001kg) can a mouse realistically attain this speed yes or no?

Shannon is playing tennis. She swings her racket to hit the tennis ball and sends the ball flying in the same direction.