How long will it take a 1630 W motor to lift a 285 kg piano to a sixth-story window 16.0 m above?
power=work/time
time=work/power=285g*16m/1630 assumeing 100 percent mechanical efficiency.
기존 보다 훨씬 높은 수준의 fool 하고 있는 것이 너무 많습니다 그래서 제가 직접 보고
cv
12_4
6
To calculate the time it takes for the motor to lift the piano to the sixth-story window, we need to use the equation:
work = force x distance
The work done by the motor is equal to the change in potential energy of the piano. The potential energy is given by the equation:
potential energy = mgh
Where:
m = mass of the piano (285 kg)
g = acceleration due to gravity (approximately 9.8 m/s^2)
h = height of the window (16.0 m)
Since the motor is lifting the piano vertically, the force exerted by the motor is equal to the weight of the piano, which is given by the equation:
force = mass x gravitational acceleration
Plugging in the values, we can calculate the force exerted by the motor:
force = 285 kg x 9.8 m/s^2 = 2793 N
Now we can plug the force and distance (16.0 m) into the work equation:
work = force x distance = 2793 N x 16.0 m = 44688 J
Since power is the rate at which work is done, we can use the equation:
power = work / time
Plugging in the power (1630 W) and the work (44688 J), we can solve for time:
1630 W = 44688 J / time
Rearranging the equation:
time = 44688 J / 1630 W = 27.4 seconds
Therefore, it will take approximately 27.4 seconds for the 1630 W motor to lift the 285 kg piano to a sixth-story window 16.0 m above.