At the gym, a woman lifts 40 kilograms of weights on the leg press machine. It takes her 0.5 seconds to raise the weights a vertical distance of 0.4 meters.
How much power does the woman generate when lifting the weights?
A) 180 watts
B) 200 watts
C) 320 watts
D) 500 watts
40*9.81*.4 = work done
power = work /second
so
P = 40 * 9.81 * .4/.5
= 314 Watts
if you used 10 m/s^2 for g you would get C
I believe B is right but I also think that D is right o.o
To calculate the power generated by the woman when lifting the weights, we can use the equation:
Power (P) = Work (W) / Time (t)
First, we need to calculate the work done by the woman. Work is defined as the force applied over a distance. In this case, the force can be calculated using Newton's second law:
Force (F) = mass (m) * acceleration due to gravity (g)
Given that the mass being lifted is 40 kilograms, and the acceleration due to gravity is approximately 9.8 meters per second squared, we can calculate the force:
Force (F) = 40 kg * 9.8 m/s^2 = 392 Newtons
Next, we calculate the work done by multiplying the force with the distance:
Work (W) = Force (F) * Distance (d)
Given that the distance lifted is 0.4 meters, we can calculate the work:
Work (W) = 392 N * 0.4 m = 156.8 Joules
Now, we need to determine the time it takes to raise the weights, which is given as 0.5 seconds.
Finally, we can substitute the values into the power equation:
Power (P) = Work (W) / Time (t)
P = 156.8 J / 0.5 s = 313.6 Watts
Rounding this value to the nearest whole number, the power generated by the woman when lifting the weights is approximately 314 Watts.
Since none of the provided answer choices match, there might be an error or rounding discrepancy in the question or the answer choices. Please double-check the question or consult with the appropriate sources to confirm the correct answer.