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a. A certain tractor is said to be capable of pulling with a steady force of 18kN while moving at a velocity of 8.0m/s. How much power in kilowatts and in horsepower is the tractor developing under these conditions?
1. A human tissue cell has a diameter of the order 1.0µm. Assuming each cell occupies a cube of 1.0 µm on one side, estimate the number of cells in 1.0cm3 of tissue.
Heliox, a breathing gas composed of a mixture of helium (He) and oxygen (O₂), is used medically for treatment in acute asthma. In medicine heliox may refer to a mixture of 21% O2 (the same as air) and 79% He. Calculate the average molar mass and density of heliox at pressure Patm = 100 kPa and room temperature t = 22°C. The molar mass of oxygen is po 16 and helium He = 4 g/mole.
1. It is given that three moles of helium gas are at a temperature of 32 °C and at a pressure of 15 atm. Helium gas is heated while being at a constant volume container. As a result, the pressure of gas triples. what is the final temperature of it
Situation: You are asked by your mother to cook pork nilaga. You have only an ordinary kettle to use for cooking. She even reminds you to save energy because we are in a state of pandemic due to covid-19. Saving resources nowadays is a must because we are not sure of the world’s economy. As a student of Physical Science and with your knowledge of properties of matter in relation to intermolecular forces, how are you going to perform your task in such a way that energy is not wasted?
A tank used for filling helium balloons has a volume of 0.600 m³ and contains 3.00 mol of helium gas at 30.0ºC. Assume the helium behaves like an ideal gas
A 5.0 ng particle of pure carbon has a net charge of +12 µC.
What fraction of electrons on this particle of carbon have been removed? ( give your answer as a decimal number to 2 s.f)
[note: MC = 12 g mol−1 and one neutral atom of carbon has 6 protons and 6 electrons.]
What is the total thermal energy of 1 mol of an ideal monatomic gas at a temperature of 0°C? (to 2 s.f and in J)
You are wearing a nice jersey that is 4.0 mm thick and is made of a material with thermal conductivity of 0.055 W m−1 K−1.
The inside surface of the jersey is at the same temperature as your skin, 26°C. The outside surface of the jersey is at a temperature of just 8.0°C.
If the jersey has a total surface area of 0.25 m2 then at what rate is heat being lost through the jersey? (to 2 s.f and in W)
How much heat is required to turn 1.5 kg of water at a temperature of 5°C into 1.5 kg of water vapour at 150°C? (to 2 s.f and in MJ)
[cwater = 4190 J kg−1 K−1, cwater-vapour = 2010 J kg−1 K−1, Lvap-water = 2256×103 J kg−1]
