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(a) What is the average kinetic energy for each type of gas molecule?
(b) What is the rms speed for each type of gas molecule?
A car plunges into a lake (water density 𝜌 = 1000 kg m-3). Using the steps below, calculate the resultant hydrostatic force on the door, and the distance from the bottom of the door to the point at which the force acts. Discuss if someone could open the door and describe the what the effect would be of opening a window. Note that the door is hinged at 𝐶𝐷.
i. Using the standard table method, find the
a. Position of the centroid (𝑥𝑐, 𝑦𝑐), its depth ℎ𝑐 and
b. second moment of area 𝐼𝑐 about the horizontal axis through the centroid
of the door by splitting it into rectangles, triangles and quarter-circles.
ii. Compute the hydrostatic force on the door using 𝐹 = 𝜌 𝑔 ℎ𝑐 𝐴. iii. Find the depth of the centre of pressure using ℎ𝑃 = ℎ𝑐 + ℎ𝐼𝑐𝑐𝐴.
Jill added 215J of heat energy to 14.5 kg of copper and 1.50 kg of water which are in
thermal contact with each other, both initially at 32.0oC. What will be their final temperature?
(Ccopper 0.385 J/goC, Cwater 4.186 J/goC).
A machinist wishes to insert a brass rod with a diameter of 3 mm into a hole with a diameter of 2.996 mm. By how much would the machinist have to lower the temperature (in °C) of the rod to make it fit the hole?
A metal rod has a length of 100cm at 200°C. At what temperature will its lenght be 99.4cm. If the linear expansivity of the material of the rod is 150.0002/K
(a) The number of molecules is very large
(b) The molecules obey Newton's laws of motion
(c) The forces between the molecules are long range
(d) The gas is a pure substance.
What is the rms speed of the molecules in sample B?
What is the rms speed of the molecules in sample B?
(a) twice that in sample A
(b) equal to that in sample A
(c) half that in sample A
(d) impossible to determine
