a meter scale is placed along the axis of a convex mirror of focal length 25cm, it's nearer end begin at a distance of 50 cm. calculate the size of the image formed?

In what direction does the medium move relative to the direction of the wave? explain.

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?