Calculate the acceleration of the cyclist

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SUMMARY

The discussion focuses on calculating the acceleration of a cyclist who comes to a stop from a speed of 21 km/h (approximately 5.838 m/s) over a distance of 15 meters. The user initially attempted to use the kinematic equation v1² - v2² = 2 * d * a but struggled to find the correct acceleration. The correct calculation yields an acceleration of -0.00649 m/s². Additionally, the coefficient of friction between the road and the bike is determined using the formula μk = - (a/g), resulting in a value of approximately 0.000662.

PREREQUISITES
  • Understanding of kinematic equations, specifically v1² - v2² = 2 * d * a
  • Basic knowledge of Newton's second law of motion (F = ma)
  • Familiarity with the concept of friction and the coefficient of friction
  • Ability to convert units from km/h to m/s
NEXT STEPS
  • Study the application of kinematic equations in different scenarios
  • Learn about the derivation and application of Newton's second law of motion
  • Research the factors affecting the coefficient of friction in various materials
  • Explore real-world applications of acceleration calculations in sports physics
USEFUL FOR

Grade 11 physics students, educators teaching motion and forces, and anyone interested in the practical applications of physics in cycling and sports dynamics.

bonfire89
Question...
Hi, I'm a Grade 11 physics student who is having a difficult time on this one question.. Any help would be greatly apretiated.


A cyclist is traveling at 21km/h when she sees a stop sign ahead. She applies the brakes and comes to a stop in 15m. The mass of the cyclist and the bike is 73kg.

a)Calculate the acceleration of the cyclist.
b) Determine the coeficient of friction between the road and the bike.


currently for question a I am atempting to use
v1^2 - v2^2 = 2 * d * a
but I am not getting the right answer


Thanks!
 
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21 km/h =~ 5.838 m/s

a = (0 - 5.838)/900 = -0.0064866666666666666666666666666667m/s^2

ΣF = -μkFN = ma

-μkmg = ma

-μkg = a

μk = -(a/g) = 6.6190476190476190476190476183673e-4


as you can see, mass don't matter.
 
awsome! thank you. I am currently doing other porblems, but I shall come back to then, and learn what you did..

THank you!
 

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