Aparallel-plate capacitor is constructed of two horizontal 15.6-cm-diameter circular plates. a 1.1 g plastic bead with a charge of -6.4 nc is suspended between the two plates by the force of the electric field between them. what is the charge on the positive (upper) plate?

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?

What makes thermal imaging cameras useful? they can detect differences in color. they can detect differences in wave speeds. they can detect differences in temperature. they can detect mechanical waves.

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight