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.
Answer:
The relative velocity of the motorcycle to a passenger in the car is 30 km/h
Explanation:
The question relates to the principle of relative velocity and reference frames
The given parameters are;
The velocity of the motorcycle, v₁ = 120 km/h
The velocity of the car, v₂ = 90 km/h
The relative velocity of an object X with regards to another object Y is the velocity the object X will seem to be moving with to an observer in the rest frame of object Y written as 
= 
- 
Therefore, the relative velocity of the motorcycle to the car is 
= v₁ - v₂, which give;
= 120 km/h - 90 km/h = 30 km/h
The relative velocity of the motorcycle to a passenger in the car = 30 km/h.
Answer:
D.
a heat force generated by the flames
Explanation:
Im not sure if that is right. the answer also maybe C.
Displacement is the area under the velocity/time graph. So for example this object's displacement in the first 3 seconds is (1/2)(3sec)(12.5 m/s)= 18.75m. (and then it starts backing up, displacement decreasing, after 3sec when velocity is negative).
But This object is never speeding up. Its velocity is smoothly decreasing at (25/6) m/s^2 (the slope of the graph). So the answer to the question is actually zero.
