The supernova remnant Cassiopeia A (Cas A) is expanding in radius at a rate of about 0.5 arc second per year. Doppler shifts show that the velocity of expansion is about 5700 km/s. How far away is the nebula

Which branches of natural science include the study of an organism that lived 10 million years ago

2) why do satelites not fall while revolving around the earth?

Abox that has self-contained cable clamps holds two light switches. a two-wire no. 12 cable with ground feeds the box, and a pair of two-wire no. 12 cables (four conductors) with ground wires leaves the box to feed the light fixtures. the second switch is fed by a no. 12 jumper wire from the first switch. which one of the following box combinations would furnish the minimum allowable volume? a. two 3-inch × 2-inch × 21⁄2-inch gangable device boxes b. two 3-inch × 2-inch × 11⁄2-inch gangable device boxes c. two 3-inch × 2-inch × 23⁄4-inch gangable device boxes d. two 3-inch × 2-inch × 21⁄4-inch gangable device boxes