Is energy absorbed or given off when an electron and a hole of a semi-conductor crystal

recombine? What are the forms of energy that can be absorbed or given off?

What is the relationship between the wavelength of a wave and its energy? A) The energy is always greater. B) They are directly proportional. C) They are inversely proportional. D) The wavelength is always greater.

following statement supports which theory? "Astronomers have observed protoplanetary disks around distant newborn stars." Big Bang theory Nebular theory Cell theory String theory

static discharge differs from electric current because static discharge is described by which of the following a. involves the movement of ions as well as electrons b. results because a force is exerted on electrons c.

What energy transformation do batteries perform? A. stored electrical - -> kinetic - -> electrical B. chemical - -> electrical C. stored heat - -> electrical D. heat - -> mechanical - -> electrical

The largest velocity reached by a falling object is its

A carnot engine rejects 80 mj of energy every hour by transferring heat to areservoir at 10°c. determine the temperature of the high-temperature reservoir and the power produced if the rate of energy addition is 40 kw.

When monochromatic light passes through the interface between two unknown materials at an angle θ where 0∘<θ<90∘, no changes in the direction of propagation of light are observed. What can be said about the two materials? A.

An object has a force of 10 newtons from the right and 17 newtons from the left. Once the object starts moving toward the right, an additional force of 7 newtons is applied from the right.

A basketball player, who weighs 600 newtons, jump 0.5 meters vertically off the floor. Calculate her kinetic energy just before hitting the floor. a) 300J b) 3000J c) 9.81m/s^2 d) 0

What are three physical properties of helium