I room is 4 m long and 2 m high density of the air in the room is 1.3 kg cubed what is the mass of air in the room?

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Acar travels in reverse. it covers 150 meters in 12 seconds what is the velocity of the car what is the speed of the car

Abeverage can is made of 3004-h19 aluminum alloy (elastic modulus 69 gpa, tensile yield strength 285 mpa, density 2.72 g/cm^3). the dimensions on the can are approximated as a thin-walled cylinder with a height of 4.83 inches, diameter of 2.60 inches. empty the can has a mass of 14.2 g. determine: a. the wall thickness of the cylinder b. assuming a pinned-pinned condition what is the critical load? c. assuming a fixed-fixed condition what is the critical load?