Physics Questions and Answers February 13, 2020

Suppose that there are two very large reservoirs of water, one at a temperature of 85.0 C, and one at a temperature of 17.0 C. These reservoirs are brought into thermal contact long enough for 42030 J of heat to flow from the hot water to the cold water. Assume that the reservoirs are large enough so that the temperatures do not change

Two rods of lengths L and L (where L L) are attached at one end with a pivot. L has its other end fixed to the ground and is always held vertical. L has its other end resting on the ground, but is not fixed. The angle between the two is . A LI al L2 2 The two rods have coefficients of linear expansion and a respectively. Both have their

Use Gauss law to determine an equation that represents the electric field in the radial direction caused by a volumetric charge distribution with density 4r Pv(r) You should note that the volumetric charge density extends to infinity. In using Gauss law, you will have to integrate to a radius of r de determine the charges enclosed within the

The electric field 6.1 cm from a very small charged object points toward the object with a magnitude of 180,000 N/C. What is the charge on the object? (k = 1/4 0 = 8.99 10 9 N m 2 /C 2 )

All working out must be shown All work must be presented in a neat and tidy manne

2. Given Figure 2 below, complete the following tasks a). Determine the position of the centroid using point P as a reference b). Determine the position of the centroid using point Q (centroid of area 2) as a reference c). Determine the position of the centroid using the Link Polygon Method d). Compare and comment on all three methods e).