Calculate the energy to accelerate and decelerate a leg

  • Thread starter Thread starter johnnyb
  • Start date Start date
  • Tags Tags
    Accelerate Energy
AI Thread Summary
The discussion focuses on calculating the energy required to accelerate and decelerate a leg during jogging, with the mass of the legs represented as m and the running speed as v*. Participants express confusion over the relationship between mass, velocity, and energy, questioning the applicability of the kinetic energy formula E = 1/2mv² due to the change in velocity involved. There is a consensus that the problem is complex and requires further exploration of the dynamics of leg movement. The conversation highlights the need for a deeper understanding of physics principles related to energy expenditure in running. Overall, the participants are seeking clarity on how to approach the calculation effectively.
johnnyb
Messages
14
Reaction score
0
In one model of jogging, the energy expenditure is assumed to go into accelerating and decelerating the legs.
If the mass of the legs is m and the running speed is v*, calculate the energy to accelerate and decelerate a leg. Assume that each leg starts in each step at a velocity v = 0 and accelerates to v=v*

Any ideas??
 
Physics news on Phys.org
Whats the relationship between mass, velocity and energy?
 
What is it just E = 1/2mv2
 
Ehh, no because there is a change in velocity. I'm stuck too.
 
Yep I have no idea
 
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...
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...
Back
Top