How far does a bicyclist travel in 30 minutes with a 2:1 gear ratio?

  • Thread starter Thread starter spikebrdr
  • Start date Start date
AI Thread Summary
To determine how far a bicyclist travels in 30 minutes with a 2:1 gear ratio, the problem is divided into two segments: the first 10 minutes of acceleration and the subsequent 20 minutes at a constant speed. The cyclist accelerates to 60 revolutions per minute (RPM) during the first segment, and the distance traveled can be calculated using the radius of the bike wheel, which is assumed to be 1 meter for simplicity. The distance for the first 10 minutes is found using the speed achieved at that point, while the distance for the next 20 minutes is calculated based on the constant speed. Overall, the total distance is the sum of the distances from both segments, assuming a typical bicycle wheel diameter of 700 mm. This approach allows for a numerical solution to the problem.
spikebrdr
Messages
12
Reaction score
0
i was wondering if anyone could give me some help with this problem

A bicyclist begins pedaling a bicycle from a complete stop. She accelerates at a constant rate until she is pedaling at 60 revolutions per minute, and then maintains this rate for the remainder of her journey. The bicyclist does not achieve a constant speed until she has been pedaling for 10 minutes. The bike is geared with a 2:1 ratio, meaning that the rear wheel of the bike turns one revolution for every two revolutions of the pedals. How far does the bike travel during a 30-minute duration?

i just need to know how to go about solving the problem and if you could include your answer that would help too.
 
Physics news on Phys.org
Are you given the radius of the wheel or the pedals? I don't see how you could come up with a numerical solution without it.

As for the problem, I'd break it up into 2 parts. The first 10 minutes is a constant acceleration problem, while the last 20 minutes is a constant speed problem. You can solve for the speed at ten minutes using the radius of the bike wheel. Use that distance to find the distance traveled in the first 10 minutes and the distance traveled in the next 20 minutes. The total distance traveled will be the sum of these 2 distances.
 
your supposed to assume the radius of the bike wheel. i was going to just make it 1 meter to make it easy.
 
So you're assuming a 2m diameter wheel http://bikekulture.com/cgi-bin/show.cgi?itemlist=&search=Calendars&start=26 . I suppose the low gearing would fit in with this. A typical bicycle wheel diameter would be 700 mm, and I would take 2:1 gearing to mean the wheel went round twice for every revolution of the pedals - that's more typical.
 
Last edited by a moderator:
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