if a ball is thrown into the air with a velocity of 45 ft/s, its height (in feet) after t seconds is given by y = 45t - 16t2. find the velocity when t = 2.

Adiver named jacques observes a bubble of air rising from the bottom of a lake (where the absolute pressure is 3.50 atm) to the surface (where the pressure is 1.00 atm). the temperature at the bottom is 4.00 ∘c, and the temperature at the surface is 23.0 ∘c.what is the ratio of the volume of the bubble as it reaches the surface (vs) to its volume at the bottom (vb)? if jaques were to hold his breath the air in his lungs would be kept at a constant temperature. would it be safe for jacques to hold his breath while ascending from the bottom of the lake to the surface?

Why does gravity have a lesser than grater effect on higher altitudes?

Are formed where bumps from two surfaces come into contact ?