the plates of a cell are connected to a 4ohms resistor and a potential difference measured across them using a potentiometer is 1.6V. If the 4ohms resistance is replaced by a 3ohms resistance and the potential difference is 1.5V, find the EMF and internal resistance of the cell.​

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?

Debbie places two shopping carts in a cart corral she pushes the first cart which then pushes a second cart what force is being exerted

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is