Acar of mass m rounds a slippery curve. the radius of curvature of the road is r, the banking angle with respect to the horizontal is θ and the coefficient of friction of the surface is µ. m µ θ what car speed would be required in order to have no frictional force between the car and the road?

Ahuge (essentially infinite) horizontal nonconducting sheet 10.0 cm thick has charge uniformly spread over both faces. the upper face carries +95.0 nc/m2 while the lower face carries -25.0 nc/ m2. what is the magnitude of the electric field at a point within the sheet 2.00 cm below the upper face? (ε0 = 8.85 × 10-12 c2/n · m2)