Explanation:
There are 5 kinematic equations, and 5 variables.
Each question will give you 3 variables and ask you to solve for a fourth.
To determine which equation to use, look at which variable is <em>not</em> included in the problem.
For example, if the question does not include time, then you need to use a kinematic equation that does not have t in it. That would be:
v² = v₀² + 2aΔx
Or, if the question does not include the final velocity, then you need a kinematic equation that does not have v in it. That would be:
Δx = v₀ t + ½ at²
Franklin had been waiting for an opportunity like this. He wanted to demonstrate the electrical nature of lightning, and to do so, he needed a thunderstorm.
He had his materials at the ready: a simple kite made with a large silk handkerchief, a hemp string, and a silk string. He also had a house key, a Leyden jar (a device that could store an electrical charge for later use), and a sharp length of wire. His son William assisted him.
Franklin had originally planned to conduct the experiment atop a Philadelphia church spire, according to his contemporary, British scientist Joseph Priestley (who, incidentally, is credited with discovering oxygen), but he changed his plans when he realized he could achieve the same goal by using a kite.
Index of refraction of a substance =
(speed of light in vacuum) / (speed of light in the substance)
Index in quartz = (2.9979 x 10⁸ m/s) / (2.0567 x 10⁸ m/s)
<em>Index = 1.4576 </em> (no units)
