Presentation on theme: "Chapter 8: Dynamics II: Motion in a Plane"— Presentation transcript:
1 Chapter 8: Dynamics II: Motion in a Plane 8.2 Velocity and Acceleration in Uniform CircularMotion8.3 Dynamics of Uniform Circular Motion8.7 Nonuniform Circular Motion
2 Stop to think 8. 2. P 214 Stop to think 8. 3. P 219 Stop to think 8. 4 Stop to think 8.2 P 214 Stop to think 8.3 P 219 Stop to think 8.4 P 226 Stop to think 8.5 P 228Example 8.3 P215Example 8.5 P217Example 8.6 P218Example 8.7 P227
3 Velocity and Acceleration in Uniform Circular Motion
4 Dynamics of Uniform Circular Motion From the Newton’s second law, a particle of mass m moving at constant speed V around a circle of radius r must have a net force ofmagnitude (mV2/r) pointing toward the center of the circle
5 Ex. 8.3 Spinning in a circleAn Energetic father places his 20 Kg child on a 5.0Kg cart to which a 2.0-m-long rope is attached. He then holds the end of the rope and spins the cart and child around in a circle, keeping the rope parallel to the ground. If the tension in the rope is 100N, how many revolutions per minute (rpm) does the cart make?
7 Problem 46: Mass m1 on the frictionless table is connected by a string through a hole in the table to a hanging mass m2. With what speed must m1 rotate in a circle of radius r if m2 is to remain hanging at rest?If m2 remains hanging at restT-m2·g=0(2) For m1, N = m1·gT =m1 V2 /r
8 A roller coaster car going around a vertical loop-the loop of radius r A roller coaster car going around a vertical loop-the loop of radius r. We’ll assume that the motion makes a complete circle and not worry about the entrance to and exit from the loop. Why doesn’t the car fall off at the top of the circle