An ideal spring has a spring constant of 15 N/m and is displaced 4 m. What is the force required to displace the spring this far?

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

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?

Ethanol has a heat of vaporization of 38.56 kj/mol and a normal boiling point of 78.4 c. what is the vapor pressure of ethanol at 14 c?