An object weigh 40n in air ,weigh 20n when submerged in water, and 30n when submerged in a liquid of unknown liquid density. what is the density of unknown of liquid?

However, had it been a real sound, the sound's pitch would have been increased by the doppler effect, since the falcon was moving the source of the sound. perpendicular to away from towards at the same speed as

Astone is dropped from a cliff and falls 9.44 meters. what is the speed of the stone when it reaches the ground? a. 13.6 m/sec b. 1.39 m/sec c. 185 m/sec d. 9.80 m/sec

What is the efficiency of an engine that does 80 j of work and exhausts 320 j of heat while taking in 400 j of heat ? a. 10% b. 20% c. 80% d. 25%