A lightbulb is 3.8 m from a wall. What is the focal length of a lens that will form an image on the wall that is twice the size of the lightbulb? (focal length is f=0.84 meters)

What is the position (measured from the bulb) of the lens.

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

Immediately upon reaching its lowest point, a falling pendulum bob has its greatest amount of energy, which is the initial amount of potential energy. a. heat; less than b. heat; more than c. kinetic; less than d. kinetic; more than

Which of the following is not a transverse wave? a) soundb) lightc) radiod) all of thesee) none of these