A MAN OF MASS 50KG ASSEND A FLIGHT OF STAIRS 5M HIGH IN 5SECOND IF ACCELERATION DUE TO GRAVITY IS10M PERSECONDSQUARE CALCULATE FOR THE POWER EXPENDED
You have chosen the distance to be about the distance which the light would move in 1 second. I cannot imagine the reflectance of the sphere would be greater than 99%, so if you solve the equation 0.99N=0.001, N would be the number of seconds it would take for the intensity of the light to drop to 0.1% of its original value. Using Wolfram Alpha, I find N≈687, a little more than 11 minutes.
see your previous post.
P = F*d/t = (M*g)*d/t = (500)*5/5 = 500 J./s = 500 Watts.
To calculate the power expended by the man while ascending the flight of stairs, we need to use the formula:
Power = Force × Velocity
First, let's calculate the force exerted by the man. The force exerted while climbing stairs is equal to the weight of the person. Weight is given by the formula:
Weight = Mass × Acceleration due to gravity
In this case, the mass is 50 kg and the acceleration due to gravity is 10 m/s^2. Therefore:
Weight = 50 kg × 10 m/s^2 = 500 N
Now, we need to calculate the velocity at which the man climbed the stairs. Velocity is given by the formula:
Velocity = Distance / Time
In this case, the distance is 5 m and the time is 5 seconds. Therefore:
Velocity = 5 m / 5 s = 1 m/s
Now, we can calculate the power using the formula:
Power = Force × Velocity
Power = 500 N × 1 m/s = 500 watts (or joules per second)
So, the power expended by the man while ascending the flight of stairs is 500 watts.