1- A 750-kg car travels at 90 km/h around a curve with a radius of 160-m. What should the banking angle of the curve be so that the only force between the pavement and tires of the car is the normal reaction force? 2- A curve of radius 150 m is banked at an angle of 10. An 800-kg car negotiates the curve at 85 km/h without skidding. Find (a) the normal force on the tires exerted by the pavement, (b) the frictional force exerted by the pavement on the tires of the car, and (c) the minimum coefficient of static friction between the pavement and tires. 3- On another occasion, the car in the previous problem negotiates the curve at 38 km/h. Find (a) the normal force exerted on the tires by the pavement, and (b) the frictional force exerted on the tires by the pavement. 4- A civil enginecer is asked to design a curved section of roadway that meets the following conditions: With ice on the road, when the coefficient of static friction between the road and rubber is 0.08, a car at rest must not slide into the ditch and a car traveling less than 60 km/h must not skid to the outside of the curve. What is the minimum radius of curvature of the curve and at what angle should the road be banked