A. A proton (q = 1.6 * 10 ^ - 19 * C) moves 4.0 * 10 ^ - 4 in the direction of an electric field that has a magnitude of 5.0 N/C b. What the change in the electrical potential energy associated with the proton ?

c. What is the potential difference between the proton's starting point and ending point?

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

If steel is more dense that lake water, why can a boat float

Could someone me find the answer to this problem.