A class is building a box that changes sunlight to heat. The device is called a solar oven. Students in the class suggest ways to make the solar oven better. Evaluate each idea. Explain whether the idea is likely to make the oven better or not and why. 1. Cover the top of the box with a piece of clear plastic that will let sunlight pass through into the box. 2. Paint the inside of the box white so that sunlight reflects from the walls of the box. 3. Put black construction paper on the floor of the box oven to absorb energy. 4. Add insulation to the outside of the box to trap heat and make the oven warmer.

To understand the electric potential and electric field of a point charge in three dimensions consider a positive point charge q, located at the origin of three-dimensional space. throughout this problem, use k in place of 14? ? 0. part adue to symmetry, the electric field of a point charge at the origin must point from the origin. answer in one word. part bfind e(r), the magnitude of the electric field at distance r from the point charge q. express your answer in terms of r, k, and q. part cfind v(r), the electric potential at distance rfrom the point charge q. express your answer in terms of r, k, and q part dwhich of the following is the correct relationship between the magnitude of a radial electric field and its associated electric potential ? more than one answer may be correct for the particular case of a point charge at the origin, but you should choose the correct general relationship. a)e(r)=dv(r)drb)e(r)=v(r)rc)e(r)=? dv(r)drd)e(r)=? v(r)r