An airplane during departure has a constant acceleration of 3 m / s². a. What is the speed that the plane reaches in 4 s? b. If the plane passes at a flight point of at a speed of 20 m / s, what is the speed 8 s later?

Awelder using a tank of volume 7.50×10^-2 m^3 fills it with oxygen (with a molar mass of 32.0 g/mol ) at a gauge pressure of 3.30×10^5 pa and temperature of 37.1 ∘c. the tank has a small leak, and in time some of the oxygen leaks out. on a day when the temperature is 23.1 ∘c, the gauge pressure of the oxygen in the tank is 2.00×10^5 pa . a) find the initial mass of oxygen. b) find the mass of oxygen that has leaked out.

Two solutions of the same uv-absorbing molecule were analyzed by uv-vis spectroscopy on the same instrument using 1 cm pathlength cells. use data from the table to calculate by what percentage the concentration of solution b is compared to that of solution a. sample absorbance at 315nm a 0.45 b 0.80

Which statements did both aristotle and ptolemy assume? check all that apply.