On an icy winter day, the coefficient of friction between thetires of a car and
ID: 1670971 • Letter: O
Question
On an icy winter day, the coefficient of friction between thetires of a car and a roadway is reduced to 3/4 its value on a dry day.As a result, the maximum speed vmaxdry at which the car can safely negotiate a curve ofradius R is reduced. The new value for this speed is whatpercentage of its value on a dry day?%
------------------------------------------------------------------------------------------------------- The radius of curvature of a loop-the-loop for a rollercoaster is 10.6 m. At the top of the loop,the force that the seat exerts on a passenger of mass m is0.70mg. Find the speed of theroller coaster at the top of the loop. (Enter your answers fromsmallest to largest.)
m/s
m/s On an icy winter day, the coefficient of friction between thetires of a car and a roadway is reduced to 3/4 its value on a dry day.As a result, the maximum speed vmaxdry at which the car can safely negotiate a curve ofradius R is reduced. The new value for this speed is whatpercentage of its value on a dry day?
%
------------------------------------------------------------------------------------------------------- The radius of curvature of a loop-the-loop for a rollercoaster is 10.6 m. At the top of the loop,the force that the seat exerts on a passenger of mass m is0.70mg. Find the speed of theroller coaster at the top of the loop. (Enter your answers fromsmallest to largest.)
m/s
m/s
Explanation / Answer
On an icy winter day, the coefficient of friction between the tiresof a car and a roadway is reduced to 3/4 its value on a dry day.As a result, the maximum speed vmaxdry at which the car can safely negotiate a curve ofradius R is reduced. The new value for this speed is whatpercentage of its value on a dry day? % the frictionalforce between the tire and car is - fs = m (-v2max) / r ==> s m g = mv2max / r ==> vmax = (s r g) Therefore v ' = (3sr g) / 4 = vmax * (3/4) = 0.866 vmax Therefore The new value for this speed is86.6% of its value on a dry day