For dry air at a temperature of 0°c and at 1 atm of pressure, electric breakdown occurs when the air is subjected to an electric field with amplitude above about 3.00 mv/m. a high-power laser is shone up into earth's atmosphere, and the laser's associated electric field ionizes the air and turns it into a conducting plasma. assume the conditions of the air are such that an electric field of 3.00 mv/m causes the air to ionize. (a) what will be the intensity (in w/m2) of a laser beam that can produce a field of this magnitude? w/m2 (b) assuming the laser is operating at this maximum intensity, what is the power (in w) delivered in a cylindrical beam with a diameter of d = 4.10 mm? remember that the intensity is defined as power per unit area; solve this relationship for power. w

Ok i am attempting to my niece attach a galvanized wire (like a tether for a dog) at the corner of two fences, making a tightwire if you will and we drilled a hole in a softball and she hits it. the ? and problem is that we can not get the wire taunt enough where it doesnt sag after hitting the ball once, and the wire sags and wobbbles. its a 15 ft rubber covered galvanized wire and one can adjust the length of the placing of the wire by having it make the corner of 2 fences become a it can be adjusted, however, with all our human strength and pliers we could not make it taunt as possible. is there anything other that attaching it to a car to do this. sorry abt the length but it would mean the world to my niece if i could solve this came up with the entire idea herself, and she is 14 and paid for the wire and did as much work as i did drilling a hole through a softball wide enough for attaching piece at each end of the wire that clips on to the fence. . any ideas welcome if serious. but awesome if it is a fact. much obliged. bucky bukowski buckman

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

Another word for electromagnetic energy is a. heat b. force c. matter d. radiation