A 7.20x10^3 N spacecraft travels away from the Earth. What is its weight when it is a) 6.38×10^3 km and b) 1.28x10^4 km from the surface of the Earth?

Aspring has a natural length of 8 m. if a 12-n force is required to keep it stretched to a length of 10 m, how much work w is required to stretch it from 8 m to 16 m? (round your answer to two decimal places.)

The two stars in a certain binary star system move in circular orbits. the first star, alpha, has an orbital speed of 36 km/s. the second star, beta, has an orbital speed of 12 km/s. the orbital period is 137 d. a) what is the mass of the star alpha? b) what is the mass of the star beta?

Why do atoms emit energy of only specific wavelengths