How long is the "muddy stretch"?
Are the bike tires rolling or skidding?
Whoever assigned this question apparently does not understand rolling motion.
A cyclist is coasting at a steady speed of 17m/s but enters a muddy stretch where the effective coefficient of friction is 0.60.
What will be the speed upon emerging?
3 answers
You need the length of muddy stretch ‘s’
ma=F(fr) =μmg,
=> a= μg.
a=(v² -v₀²)/2s
μg=(v² -v₀²)/2s
v= sqrt(2sμg+ v₀²)
ma=F(fr) =μmg,
=> a= μg.
a=(v² -v₀²)/2s
μg=(v² -v₀²)/2s
v= sqrt(2sμg+ v₀²)
Elena apparently does not take into account that unless a tire is skidding, the friction at the point of contact does not slow the bike down. The point of contact is an instant center, kinematically speaking.
1 answer