power and time
Power :-It is the work done in unit time.
Power (p) = Total workdone
Total Time
Which is equal to 1 Watt. Power in watts = w/t = F.s/t = F x V
In M.K.S. system the unit is 1 kgf meter/sec. One horse power is = 75 kg metre/sec or 4500 kgf metre/min.
1HP (metric) = 735.5 Watts
1HP (British) = 746 Watts = 0.746 KW
1 KW = 1.34 HP
Power input is the power given to a machine to do work.
Power output is what we get out of the machine.
Power output is always less than power input due to friction in the
machine.
The ratio between power output to power input is efficiency of the machine and it is expressed in
percentage.
Efficiency = power output ×100%
Power Input
Power (p) = Total workdone
Total Time
The SI unit of power is
= 1Nm/sec = 1joule /secWhich is equal to 1 Watt. Power in watts = w/t = F.s/t = F x V
In M.K.S. system the unit is 1 kgf meter/sec. One horse power is = 75 kg metre/sec or 4500 kgf metre/min.
1HP (metric) = 735.5 Watts
1HP (British) = 746 Watts = 0.746 KW
1 KW = 1.34 HP
Power input is the power given to a machine to do work.
Power output is what we get out of the machine.
Power output is always less than power input due to friction in the
machine.
The ratio between power output to power input is efficiency of the machine and it is expressed in
percentage.
Efficiency = power output ×100%
Power Input
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