Fred points a toy laser gun at a wall. Considering that the frequency of the gun's light is 4.91 × 1014 hertz and that Planck’s constant is 6.61 × 10-34 joule·seconds, what is the energy of the laser light?

Gam radio signals can usually be heard behind a hill, but fm often cannot. that is, am signals bend more than fm. explain. (radio signals, as we shall see, are carried by electromagnetic waves whose wavelength for am is typically 200 to 600 m and for fm about 3 m.)

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

Amira pulls a 3 pound wagon 4 feet. how much work has she done?