Energy of a photon : E = hf The photoelectric effect works like this. If you shine light of high enough energy on to a metal, electrons will be emitted from the metal. Light below a certain threshold frequency, no matter how intense, will not cause any electrons to be emitted.
The Boogie Board Jot 8.5 is an uber-slim slate with a black 8.5â³ screen. The stylus clicks into the opening under the screen. When you use the stylus it writes on the screen in a bright green color. The company claims this board is 50% brighter than their previous Jot model.
CONS / The 2-amp battery runs out of power faster than the 4-amp battery. VERDICT / The Kobalt 40-Volt cordless mower is the best electric lawn mower for flat yards up to 1/3 of an acre in size. The Kobalt 40-Volt cordless mower is a powerful, efficient electric lawn mower that gives your lawn a clean trim while requiring less effort to maneuver than a heavy gas-powered mower. Not only is it a clean-energy replacement for your gas lawn mower, it is backed by a generous five-year warranty. This lawn mower is one of the best electric lawn mowers available and is our Top Ten Reviews Silver Award winner. Kobalt 40-Volt Cordless Mower KM2040X-06 Visit Site.