# Posts by aris

Total # Posts: 4

**math 115a**

two points A and B 80 ft apart lie on the same side of a tower and in a horizontal line through its foot . If the angle of elevation of the top of the tower at A is 21 degrees and B is 46 degrees , find the height of the tower.

**Physics**

(2.00 L) x (273 / (20 + 273)) / (22.414 L/mol) = 0.083139 mol air in the "empty" container (7.20 g H2O) / (18.01532 g H2O/mol) = 0.39966 mol H2O added Supposing all the water vaporized: PV = nRT P = nRT / V = (0.083139 mol + 0.39966 mol) x (0.08205746 L atm/K&#...

**physics**

a red blood cell travels at a speed of 40 cm/s in a large artery. a sound with a frequency of 100 kHz enters a blood opposite the direction flow. calculate the frequency of sound reflected from the cell and detected by a receiver. (v = 1500 m/s)

**maths**

1/3 equals to 4/12, 1/4 equals to 3/12. 3/12 plus 4/12 equals 7/12. Therefore 5/12 left