Acrate of 890 kg gets raised to a height of 2.1m. calculate the crate's gravitational potential energy.

Asubmarine has a "crush depth" (that is, the depth at which water pressure will crush the submarine) of 250 m. what is the approximate pressure (water plus atmospheric) at this depth? (recall that the density of seawater is 1025 kg/m3, g = 9.81 m/s2, and 1 kg/(ms2) = 1 pa = 9.8692 10-6 atm.) a. 34.8 atm b. 24.8 atm c. 25.8 atm d. 7.8 atm

Anybody wanna ? (picture included? )

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.