The temperature u in a metal ball is proportional to the square of the distance from the center of the ball. Find the rate of heat flow across a sphere S of radius r with center at the center of the ball. SOLUTION Taking the center of the ball to be the origin, we have u(x, y, z)

Question 11 of 13 (1 point) jump to question: a stairway, ladder, or ramp must be present in excavations in which of the following situations? a. all trenches must have access/egress b. the trench is more than 15 feet wide but only 1 ½ feet deep c. the trench is more than 4 feet deep and the devices must be within 25 feet of all workers

The solid that is formed and usually sinks to the bottom of a solution is the

Which planet do you think would be easiest for humans to colonize some day?