If you mean what types of measurements are used to measure in outer space, I believe it’s light-year, astronomical unit and intergalactic measurements, but I’m not completely sure.
Hopefully this helps...
The method to choose depends on what information you have, and
on what you can measure. Here are a few possible methods:
-- Measure the period. Start your clock when one peak
of the wave passes you. Stop the clock when the next
peak passes you. The time between the two peaks is
the wave's period.
-- Divide the wave's wavelength by its speed. That quotient
is the wave's period.
-- Use an electronic frequency meter to measure the wave's
frequency. Then take its reciprocal (divide ' 1 ' by it). The
result is the wave's period.
Answer:
Some work input is lost to friction
Explanation:
The efficiency of a machine is defined as:
(1)
where
is the work output
is the work input
Due to the law of conservation of energy, the work output can never be larger than the work input (because energy cannot be created). Moreover, in real machines part of the work input is lost due to the presence of frictions: as a result, part of the energy in input is converted into thermal energy or other forms of energy, and so the work output is smaller than the work input, and so the ratio (1) becomes less than 1, and so the efficiency is less than 100%.