A fire hose held near the ground shoots water at a speed of 5.7 m/s. At what angles should the nozzle point in order that the water land 2.0 m away? Why are there different angles?
It is normal for flashlights to be made into lasers. The less-powerful laser pointers are usually pen-style with 2 mm beam diameter, but more powerful ones have a host (housing) that's the same as for a flashlight, such as Ultrafire 501b, That kind usually has a 5 mm beam, but also an adjustable focusing lens. Believe it or not, plastic goggles can actually be great protection from a laser, but only if they were designed to handle the power of whatever kind of laser it is. Laser safety goggles are usually characterized by what wavelength they protect against, how much light they block out (the OD rating) and the maximum power they can handle. Green lasers usually have a wavelength of 532nm, so search on Google Images for laser safety goggles and 532nm. You will see lots of red goggles. Green laser pointers actually have an infrared diode inside that puts out 808nm, then a crystal in front of that which turns it into 1064nm, then another crystal that converts it to 532nm. Since there is some leakage, the goggles need to block out all three wavelengths.
Old fashioned soda acid fire extinguishers contain baking soda in water and an acid. The combination of the 2 forms CO2 and the gas forces out the water. These must be inverted. For type A fires only There are CO2 extinguishers which have a large cone on them on the hose. They contain CO2 gas under pressure. These can be used on electrical or liquid fires.B+C Many dry ABC extinguishers contain PKP powder. It is important to shake these as the powder can harden in the bottom. Do not invert these while using them. Some newer extinguishers have a different powder, but are used the same way. ABC Remember PASS pull the pin aim at the base of the fire squeeze the handle sweep back and forth
