If an object has a mass of 81 kg, what is its approximate weight on earth?

Which of the following is the phase that results when the moon is on the opposite side of the earth from the sun? a. quarter moon b. crescent moon c. new moon d. full moon

Aball is thrown horizontally from a cliff at 8m/s .in what direction is the ball moving 2s later?

On a mild saturday morning while people are working inside, the furnace keeps the temperature inside the building at 23degreesc. at noon the furnace is turned off, and the people go home. the temperature outside is a constant 16degreesc for the rest of the afternoon. if the time constant for the building is 3 hr, when will the temperature inside the building reach 18degreesc? if some windows are left open and the time constant drops to 2 hr, when will the temperature inside reach 18degreesc?