Question

5. A car travels at a constant speed of 20 m/s around a horizontal circular track of radius 80 m. The tires roll without slipping. We can conclude that the coefficient of static friction between the tires and track:

Answer 1

.5

Step-by-step explanation:

First we define the variables

v=20

r=80

Next we construct our formula, since our tires do not slip, our centripetal force is equal to our friction

ma=mg*u

We calculate our centripetal force through finding our acceleration (v^2/r) and assuming our mass is a variable m (we cancel it out later).

mv^2/r = mg*u

All we have left is substitution and simplification

400m/80=mg*u

5=g*u

G is our gravitational acceleration (I will use 10, use 9.8 instead if you prefer)

5=10*u

u=.5