4. Three students attempt to move a stationary mass of 26.0kg (in the X-Y plane). One student pulls with a force of 85N (N25E), another pushes with a force of 60N [N] and the other student exerts a force of 8ON [N25W]. An
additional force of 180N [S] impedes the motion of the mass. If the mass is moving fortifor 2.0 seconds,
determine the displacement of the mass. /3

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.