The height of one step is 18.5 cm and there are 10 steps. I ran twice. (up and down, up and down)
So do you do 18.5 X 20=370 cm.?
might be correct but not sure...
My weight in pounds is 140, in kg it is 63 and in newtons it is 190.4
to find work----- to find work,(W=fxd) do you multiply 190.4X0.37
I converted the 370 into meters because work is measure in Newtons meter Joules.
How do you find power? (p=w/t)
My time was 16.79.....will it be 140/16.79?
2007-01-27 12:31:19 · 5 answers · asked by ghettoco 1 in Science & Mathematics ➔ Mathematics
Power = Work/time
Work = mg(change in height)
So the work you did when you ran up the stairs the first time was
W=190.4N*3.7m = 703 J
The rate at which you did work or your power output was
P=703J/(16.79/4) = 167 Watts
Now, when you ran back down, you did -703 J of work, so your total work for the up and down trips was ZERO. And your total power was Zero too.
2007-01-27 12:45:12 · answer #1 · answered by Dennis H 4 · 0⤊ 0⤋
Your basic idea is correct because you are only doing work going up the the steps. However 370cm is 3.70 meters and 63kg in newtons is 63 * 9.8 = 617 . Now your equations should work out correctly.
2007-01-27 20:49:28 · answer #2 · answered by rscanner 6 · 0⤊ 0⤋
18.5*20 seems right for the distance, to find work, w=f*d, f=ma=63*9.8=617.4N, thus W= 617.4N*3.70m=2284.38.
And lastly, P = 2282.38/16.79 = 135.06 Watts
2007-01-27 20:42:05 · answer #3 · answered by goldenflaws 2 · 0⤊ 0⤋
ROTFLMSFAO!!!!!!!!!!!!!!
At the end of your little exercise session you had travelled a *total* vertical distance of zero. So..... No net vertical displacement, no work done and the power was 0 J/s.
Doug
2007-01-27 20:46:00 · answer #4 · answered by doug_donaghue 7 · 0⤊ 0⤋
just to confirm your words ..."I ran twice. (up and down, up and down) "...would it be 40 steps then?
2007-01-27 20:38:04 · answer #5 · answered by Neo 2 · 0⤊ 1⤋