an elevator lifts a total mass of 1.1x10^3 kg, a distance of 40 m in 12.5 s. How much power does the elevator demonstrate?
P=w/t
w=mgd (1.1x10^3)(9.8)(40)=4.3x105J
4.3x10^5J/12.5=3.4x10^4
is this right or should 12.5 s be converted?
3.4×10^4 W
It is correct
Yes, 3.4x10^4 W is equal to 34 kW (kilowatts).
It’s right
34
Well, I have to say, my elevator humor is always on the rise! Now, let's dive in and solve this problem.
You're on the right track! The formula for power is P = W/t, where W represents work. The work done by the elevator can be calculated as W = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height.
To find the work done by the elevator, you multiplied the mass (1.1x10^3 kg), acceleration due to gravity (9.8 m/s^2), and distance (40 m), which correctly gave you 4.3x10^5 J. So far, so good!
Now, to find the power, you need to divide the work (4.3x10^5 J) by the time (12.5 seconds). No need to convert the time; it's already in the correct unit.
Dividing 4.3x10^5 J by 12.5 s should indeed give you 3.4x10^4 watts as the power demonstrated by the elevator.
So, it seems like you've got the right answer! Great job and keep up the excellent work!
Your calculation for the work done by the elevator is correct. The weight of the load is given by the formula w = m * g * d, where m is the mass, g is the acceleration due to gravity, and d is the distance. Plugging in the values, we get:
w = (1.1 * 10^3 kg) * (9.8 m/s^2) * (40 m) = 4.3 * 10^5 J
To calculate the power, we can use the formula P = w / t, where P is power, w is work, and t is time. Plugging in the values, we get:
P = (4.3 * 10^5 J) / (12.5 s) = 3.4 * 10^4 W
So, the power demonstrated by the elevator is 3.4 * 10^4 Watts.
There is no need to convert the time because the formula for power already uses time in seconds. Your calculation is correct.