Author Question: An object having a fixed emissivity of 0.725 radiates heat at a rate of 10 W when it is at an ... (Read 103 times)

RRMR · **on:** Jul 29, 2018

An object having a fixed emissivity of 0.725 radiates heat at a rate of 10 W when it is at an absolute temperature T. If its temperature is doubled to 2T, at what rate will it now radiate?

A) 20 W
B) 40 W
C) 80 W
D) 160 W
E) 320 W

Question 2

A tennis ball bounces on the floor three times, and each time it loses 23.0 of its energy due to heating. How high does it bounce after the third time, if we released it from the floor?

A) 180 cm
B) 18 cm
C) 180 mm
D) 240 cm