Ideally, a hydrogen fuel-cell vehicle has no environmental impact. Energy is produced by combining hydrogen with oxygen pulled from the atmosphere, and the tailpipe emission is water. The hydrogen fuel could come from a number of sources (Iceland recently started pulling it out of the ground).
A fast shutter speed such as 1/400th of a second will produce a series of crisp frames that have a choppy look when played back. A slow shutter speed such as 1/30th of a second, on the other hand, will produce a series of slightly blurred frames that have a smoother look when played back.
Many sports use very fast shutter speeds to capture the peak moment and freeze it in time. If the subject of your photo is not moving, or you want to show the passage of time (with a running river or waterfall), then you can use a slower shutter speed.hutter speed is measured in fractions of seconds and seconds. Here is an example of shutter speed numbers, from fast to slow: 1/2000 1/1500 1/1000 1/750 1/500 1/350 1/250 1/180 1/125 1/90 1/60 1/45 1/30. Realize that 1/2000 of a second is incredibly fast and is not a shutter speed that you will typically use.