Physics Problem, back to the future physics?

Question

In the movie back to the future, marty travels back to the future useing the delorian and lightning. Doc said that the car needed 1.21 gigawats to time travil. my question is can lightning hold 1.21 gigawats

Answer 1

sure. if it didn't Marty would have been stuck there, and they wouldn't have been able to make Back to the Future 2 & 3

Answer 2

Good question - power is a product of voltage and current. It is also the enery expended over time. Let's look a the last definition first.

To get 1.21 GW, you could release 1.21 Joules of energy (nothing really) in 1 nanosecond. So a little energy can have a high instantaneous power. Lighting strikes last about 0.01 seconds so scaling up from our 1.21 J example, the bolt would require an energy of 12.1 MJ - 12 million Joules. A stick of dynamite (about 1 kg) has about 2 MJ of energy so the bolt would have to have the energy equivalent to 6 sticks of dynamite - not unreasonable.

Now let's consider teh electrical definition of voltage times current. The breakdown strength of air is about 1MV/cm. Let's say that under the right conditions, this drops by a factor of 10, and a lighting bolt is about 1 km long. The potential difference (volatge) is around 10 GV. That means the current only has to be about 0.12 amps - a bit small probably.

SO just looking at rough orders of magnitude it seems more than reasonable that lighting could have 1.21 GW of power - it may have even more.

Answer 3

they could use the Newtonian equation: - s = u.t + 0.5.g.t^2 To degree gravity interior the vacuum surrounding the Moon, all they might ought to do is degree, very properly, the time of fall from relax for a small weight. the load could desire to be dropped from an electronically opened capture - which in turn started an extremely precise clock. The clock could be stopped, because of the fact the falling weight exceeded a mild beam, in simple terms above the exterior of the Moon. If the area 's', of fall for the load, between the launch capture (clock initiate) and the sunshine beam (clock supply up) is properly often happening then the equation in simple terms will become: - s = 0.5.g.t^2 the place 't' is the time of fall and 'g' is the Moon's gravitational acceleration (^2 skill squared). This equation rearranges to furnish: - g = 2.s/(t^2) for this reason, the two scholars could desire to very in simple terms degree the gravitational acceleration on the Moon.

Answer 4

The strength of a lightning bolt is dependent on the voltage that produces it. It is not impossible that a lightning bolt could well exceed 5 gigawatts/hr because the duration is so small.
Time travel of any kind is pure hogwash.

Answer 5

according to wikipedia, it delivers 100 terawatts. (note 1 terawatt is equivalent to 1,000 gigawatts)