A motor boat moves at a steady speed of 8 m s-1 if the water resistance to the motion of the boat is 2000 N calculate the power of the engine
Newton #1 - If there is no NET force, momentum is constant. Here speed is steady (I assume in a straight course) and mass is constant so net force is zero.
Newton #2 - Action is equal and opposite to reaction. So Propulsion force forward must be equal and opposite to resistance.
Therefore - Propulsion force = 2000 N
Work = Force * distance
Power = work /second = force * distance/second
so
Power = 2000 N * 8 meters / second
= 16,000 Joules/second or Watts
This must be a Destroyer of something :)
physics - Damon, Tuesday, July 22, 2014 at 4:37am
Newton #1 - If there is no NET force, momentum is constant. Here speed is steady (I assume in a straight course) and mass is constant so net force is zero.
Newton #3 - Action is equal and opposite to reaction. So Propulsion force forward must be equal and opposite to resistance.
Therefore - Propulsion force = 2000 N
Work = Force * distance
Power = work /second = force * distance/second
so
Power = 2000 N * 8 meters / second
= 16,000 Joules/second or Watts
This must be a Destroyer of something :)
given speed =distance /time =8m/s
force = 2000N
power =work /time=force *displacement /time
=2000*8/1
=16000j/s
To calculate the power of the engine, we need to use the formula:
Power = Force x Velocity
In this case, the force is the water resistance (2000 N) and the velocity is the boat's speed (8 m/s).
So, we can substitute these values into the formula:
Power = 2000 N x 8 m/s
Power = 16,000 Nm/s
However, we need to convert Nm/s to a more commonly used unit of power, such as watts (W). We know that 1 watt is equal to 1 joule per second (1 W = 1 J/s).
Therefore, we can convert Nm/s to W by dividing by the conversion factor of 1 J/s:
Power = 16,000 Nm/s ÷ 1 J/s
Power = 16,000 W
So, the power of the engine is 16,000 watts.