A Star is said to be born when ? a) A red giant collapses on itself and becomes a black hole
b) a protostar reaches a temperature high enough for nuclear fusion to begin
c) pressure within a protostar becomes so great that a supernova occurs
d) a dark, cool interstellar cloud begins to contract

Jake has a nine month old son. how can he build his self esteem

Power can be defined as a. the distance over which work was done. b. how much work can be done in a given time. c. all the work in an given area. d. the energy required to do work.

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg