A flashlight is powered by 4, 1.5-volt batteries, which are connected in series. The bulb draws 720mA or 0.72 amps when turned on. Calculate the resistance of the bulb.

Does heating a metal wire increase or decrease its electrical resistance? why?

When you hold a rectangular object, how does the area of the side that is resting on your hand affect the pressure and the force that the object exerts?

Find an expression for the electric field e⃗ at the center of the semicircle. hint: a small piece of arc length δs spans a small angle δθ=δs /r, where r is the radius. express your answer in terms of the variables q, l, unit vectors i^, j^, and appropriate constants.