How much energy does it take to climb stairs?

  • Thread starter Thread starter uno
  • Start date Start date
  • Tags Tags
    Efficiency
AI Thread Summary
To calculate the energy expended by a 60 kg person climbing stairs to a height of 25 m, the formula Wg = mgh is used, resulting in an energy requirement of 14,715 J. However, considering muscle efficiency at about 20%, the actual energy consumed will be higher than this output. Efficiency is defined as work-out divided by work-in, indicating that the work input must account for this efficiency loss. Therefore, to find the total energy expenditure, one must divide the work output by the efficiency percentage. This discussion emphasizes the importance of understanding both the mechanical work done and the biological efficiency of muscle energy conversion.
uno
Messages
38
Reaction score
0
1. Efficiency is defined as work-out/work-in. Muscles operate with an efficiency of about 20% in converting energy internally into work externally. Accordingly, how much energy will be expended by a 60 kg person in the process of ascending several flights of stairs to a height of 25 m?



2. I was using Wg=mgh



3. I used the formula to get an answer of 14715 J, but I'm not sure where to go from here.
 
Physics news on Phys.org


Eg yes does equal mgh

Now rmbr efficiency is work out (the amount of energy you get) / work in (how much work you actually put in)

Now we know efficiency is 20 percent and what is the work you get out (hint)
 


Got it. Thanks.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Power required to climb a 20-m-tall building in 55s
Replies
1
Views
1K
Muscles opperating with efficiency of 18%
Replies
4
Views
2K
How Does Climbing Stairs Compare to Lighting a Bulb in Energy Use?
Replies
9
Views
7K
How Much Work Is Involved in Climbing Stairs for a 60kg Person?
Replies
12
Views
23K
Calculating the Work Required to Climb Stairs
Replies
14
Views
8K
How Does Tension Contribute to Climbing Power?
Replies
4
Views
1K
Power & Stair Climbing: Reviewing Old Homework
Replies
2
Views
2K
Heat and work -- how much energy to climb the rope....
Replies
6
Views
2K
Calculating Joe's Climb Efficiency
Replies
8
Views
5K
Calculating Work for Climbing Stairs
Replies
1
Views
5K

Hot Threads

Recent Insights

Back
Top