A 35 g bullet with a velocity of 75 m/s hits a 7 kg block and the bullet goes inside the block. The block moves and compresses the spring. Find the maximum compression on the spring where the block momentarily comes to a stop. The spring constant is 25 N/m.

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?