The objective lens of the refracting telescope at the lick observatory in california has a focal length of 57 ft. what is the refractive power of this lens? what focal length (mm) eyepiece would give a magnification of 1000x for this telescope?

Aspring with a mass of 2 kg has a damping constant 14 kg/s. a force of 3.6 n is required to keep the spring stretched 0.3 m beyond its natural length. the spring is stretched 0.6 m beyond its natural length and then released. find the position of the mass at any time t. (assume that movement to the right is the positive x-direction and the spring is attached to a wall at the left end.)

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star

Chemical energy is a form of energy. a. heat b. kinetic c. potential d. electromagnetic