Presentation on theme: "Chapter 8: Dynamics II: Motion in a Plane 8.2 Velocity and Acceleration in Uniform Circular Motion 8.3 Dynamics of Uniform Circular Motion 8.7 Nonuniform."— Presentation transcript:
Chapter 8: Dynamics II: Motion in a Plane 8.2 Velocity and Acceleration in Uniform Circular Motion 8.3 Dynamics of Uniform Circular Motion 8.7 Nonuniform Circular Motion
Stop to think 8.2P 214 Stop to think 8.3P 219 Stop to think 8.4P 226 Stop to think 8.5P 228 Example 8.3P215 Example 8.5P217 Example 8.6P218 Example 8.7 P227
Velocity and Acceleration in Uniform Circular Motion
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 of magnitude (mV 2 /r) pointing toward the center of the circle
Ex. 8.3 Spinning in a circle An 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?
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? (1) If m2 remains hanging at rest T-m2·g=0 (2) For m1, N = m1·g T =m1 V 2 /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