Help with Homework? 1. A circular disk of radius 30 cm is rotating with an angular acceleration of 1 radian/ s2. What is the tangential acceleration of a point on the rim of the disk? What is its centripetal acceleration if the angular speed is 3 rev / s? 2. A 980 Kg car traveling at 20 m/s rounds a curve of radius 40 m. What is the friction force that must act on the car to keep it in its circular path? 3. An object with a mass of 100 Kg is dragged up an incline by applying a force F. The total distance moved along the incline is 200 m and the vertical height gained in moving this distance is 20 m. What is the magnitude of the force F if friction is negligible? (Assume g = 10 m/s2) 4. What is the acceleration of an object that slides down an inclined plane that has a gradient of 1:4 (increases in height by 1 m when you travel along the plane 4 m) Ignore friction and assume g = 10 m/s2. 5. A force of 5 N is applied to a door perpendicular to its face at a distance of 0.75 m from its hinge. What is the torque on the door about the hinge? 6. The nut on a car wheel requires a torque of 75 N.m for opening it. A wrench 25 cm long is used to open the nut. What is the minimum force needed to open the nut?