Tweedeldum and tweedledee are carrying a uniform wooden board that is l = 3.00 m long and has a weight of w = 160 n . if tweedledum applies an upward force of magnitude f1 = 60.0 n at the left end of the board, at what point and with what magnitude f2 of force does tweedledee have to lift for the board to be carried?

Acylinder with a movable piston contains 11.7 moles of a monatomic ideal gas at a pressure of 1.32×10^5 pa. the gas is initially at a temperature of 300 k. an electric heater adds 43200 j of energy into the gas while the piston moves in such a way that the pressure remains constant. cp=20.79 j k^−1 mol^−1 for a monatomic ideal gas, and that the number of gas molecules is equal to avogadro's number (6.022×10^23) times the number of moles of the gas. (a) what is the temperature of the gas after the energy is added? (b) what is the change in volume of the gas? (c) how much work is done by the gas during this process?

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i. e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2