What type of elastic force is present in the strings on a guitar?
a) compression
b) tension
c) friction
d) inertia

How many molecules are present in 3 mols of silicon dioxide (sio2)?

What is the kinetic energy of a baseball moving at a speed of 40 m/s if the baseball has mass of 0.15 kg?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?