Two identical 7.10-g metal spheres (small enough to be treated as particles) are hung from separate 700-mm strings attached to the same nail in a ceiling. Surplus electrons are added to each sphere, and then the spheres are brought in contact with each other and released. Their equilibrium position is such that each string makes a 17.0 ° angle with the vertical.

How many surplus electrons are on each sphere?

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.

Hi , i am new here can anyone me out with this question why is space black after having so many shining objects like sun , moon , stars