Momentum of biker dragging foot

Thread starter StotleD
Start date Jul 11, 2005
Tags

Momentum

AI Thread Summary

The discussion centers on calculating the change in momentum for a rider and bike as the rider slows from 8.1 m/s to 4.0 m/s. Momentum is defined as the product of mass and velocity. The total mass of the system is 83.6 kg (77.0 kg rider plus 6.6 kg bike). The change in momentum is calculated using the initial and final velocities. The conversation concludes with the original poster expressing satisfaction after solving the problem.

Jul 11, 2005

StotleD

A 77.0 kg rider sitting on a 6.6 kg bike is riding along at 8.1 m/s in the positive direction. The rider drags a foot on the ground and slows down to 4.0 m/s still in the positive direction. What is the change in momentum of the rider and bike?

Physics news on Phys.org

Jul 11, 2005

Doc Al

Mentor

What's the definition of momentum?

Jul 11, 2005

mathmike

What Have You Done So Far

Jul 14, 2005

StotleD

I figured this out, 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 '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 »

Thread 'Explain this asphalt sheen'

This problem is two parts. The first is to determine what effects are being provided by each of the elements - 1) the window panes; 2) the asphalt surface. My answer to that is The second part of the problem is exactly why you get this affect. And one more spoiler:

View full post »