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0 of 5 A rider on a mountain bike is traveling to the left. Each wheel has an angular velocity, . Is the sign of positive or negative? Angular Variables Positive Negative Your Prediction: 0 of 5
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0 of 5 A rider on a mountain bike is traveling to the left. Each wheel has an angular velocity, . Is the sign of positive or negative? Angular Variables • Positive • Negative Your Prediction:
0 of 5 A rider on a mountain bike is traveling to the left. Each wheel has an angular velocity, . Which direction does the angular velocity vector point? Angular Variables • Into the board • Out of the board Your Prediction:
0 of 5 The cyclist is passing another rider by increasing her speed. Her wheel’s angular velocity increases from +21.7 rad/s to +28.5 rad/s in 3.5 seconds. Which direction does the angular acceleration vector, , point? Angular Variables • Into the board • Out of the board Your Prediction:
0 of 5 The cyclist is passing another rider by increasing her speed. Her wheel’s angular velocity increases from +21.7 rad/s to +28.5 rad/s in 3.5 seconds. What is the magnitude of ? Angular Variables • 8.1 rad/s2 • 6.2 rad/s2 • 1.9 rad/s2 • -1.9 rad/s2 Your Prediction:
0 of 5 The cyclist now coasts for 10.7 s. Her wheel’s angular velocity decreases from 28.5 rad/s to 15.3 rad/s. What is the direction of ? Angular Variables • Into the board • Out of the board Your Prediction:
0 of 5 The cyclist now coasts for 10.7 s. Her wheel’s angular velocity decreases from 28.5 rad/s to 15.3 rad/s. What is the magnitude of ? Angular Variables • +1.4 rad/s2 • -1.4 rad/s2 • +1.2 rad/s2 • -1.2 rad/s2 Your Prediction:
0 of 5 A rod pivots about one end. A force is applied in order to cause the rod to rotate about its pivot point (its axis of rotation). Which configuration is most effective at causing the rod to rotate? Torque - I • 1 • 2 • 3 • 4 • 5 • 6 Your Prediction: F F F F Axis Of rotation F F (1) (2) (3) (4) (5) (6)
0 of 5 What does a net torque tend to do to an object? Torque – II a • Causes it to accelerate • Causes its mass to change • Causes its velocity to change • Causes it to rotate Your Prediction:
0 of 5 How do clockwise and counter-clockwise torques compare when a system is in equilibrium (balanced) Torque – II b • Clockwise is always greater • Counter-clockwise is always greater • Either one can be greater or they can be the same • They are the same Your Prediction:
0 of 5 The broom is balanced on the fulcrum, as shown. Where is the center of mass of the broom? Center of Mass - II • 1 • 2 • 3 Your Prediction: 1 2 3 Your Observation:
0 of 5 If we cut the broom into two pieces at the center of mass, which half is heavier? Torque • The bristle end • The handle end • Both are the same weight • Need more information Your Prediction: 1 2 3 Your Observation:
55 g 0 of 5 A 145 g meter stick is suspended at the 50 cm mark. If 55 g are added at the 75 cm mark, how many grams should be added at the 25 cm mark to keep the system in equilibrium? Torque Demonstrator - I • 25 g • 55 g • 75 g • 145 g • 1495 g Your Prediction: 0 25 50 75 100 Your Observation: ? g
0 of 5 A 145 g meter stick is suspended at the 50 cm mark. If 25 g are added at the 90 cm mark, how many grams should be added at the 40 cm mark to keep the system in equilibrium? Torque Demonstrator - II • 25 g • 40 g • 90 g • 100 g • 1495 g Your Prediction: 0 25 50 75 100 Your Observation: 25 g ? g
0 of 5 A 145 g meter stick is suspended at the 25 cm mark. How many grams should be added at the zero cm mark to keep the system in equilibrium? Torque Demonstrator - III • 25 g • 55 g • 90 g • 100 g • 145 g • 1495 g Your Prediction: 0 25 50 75 100 ? g Your Observation:
5 g 0 of 5 A 145 g meter stick is suspended at the 5 cm mark. If 5 g are added at the 75 cm mark, how many grams should be added at the 0.4 cm mark to keep the system in equilibrium? Torque Demonstrator - IV • 25 g • 55 g • 90 g • 100 g • 145 g • 1495 g Your Prediction: 0 25 50 75 100 ? g Your Observation:
F 0 of 5 A cylindrical section of small radius connects two disks of larger radius. A ribbon is wrapped around the smaller, middle section and pulled, as shown.Which direction does the system rotate? Torque Wheel - I • Clockwise • Counter-clockwise • It will slide without rotating • Need more information Your Prediction: Front View Side View Your Observation:
0 of 5 A cylindrical section of small radius connects two disks of larger radius. A ribbon is wrapped around the smaller, middle section and pulled, as shown.Which direction does the system rotate? Torque Wheel - II • Clockwise • Counter-clockwise • It will slide without rotating • Need more information Your Prediction: Front View Side View Your Observation: F
0 of 5 A cylindrical section of small radius connects two disks of larger radius. A ribbon is wrapped around the smaller, middle section and pulled, as shown.Which direction does the system rotate? Torque Wheel - III • Clockwise • Counter-clockwise • It will slide without rotating • Need more information Your Prediction: Front View Side View F Your Observation:
0 of 5 Rank these objects from greatest moment of inertia to lowest moment of inertia: a solid sphere, a solid cylinder, and a hollow cylinder: Moment of Inertia - I • Sphere Hollow Cylinder Solid Cylinder • Sphere Solid Cylinder Hollow Cylinder • Hollow Cylinder Solid Cylinder Sphere • Solid Cylinder Sphere Hollow Cylinder Your Prediction: Greatest Middle Lowest Your Observation:
0 of 5 A solid sphere, a solid cylinder, and a hollow cylinder are placed at the top of an incline. After being released from rest, in which order do they reach the bottom: Moment of Inertia - II • Sphere Hollow Cylinder Solid Cylinder • Sphere Solid Cylinder Hollow Cylinder • Hollow Cylinder Solid Cylinder Sphere • Solid Cylinder Sphere Hollow Cylinder Your Prediction: First Second Third Your Observation:
0 of 5 An ice skater is spinning with her arms extended. She then pulls her arms in close to her body.What happens to her angular speed of rotation? Angular Momentum - I • It increases • It stays the same • It decreases • It may increase, decrease, or stay the same Your Prediction: Your Observation:
0 of 5 What is that little propeller for on the back of a helicopter? Helicopter - I • It is needed for steering the helicopter • It is needed to prevent the helicopter from spinning uncontrollably • It really doesn’t do that much Your Prediction: Your Observation:
0 of 5 This helicopter has two large propellers. The front propeller is spinning clockwise, as seen from above. Which direction does the rear propeller spin? Helicopter - II • Clockwise • Counterclockwise • It really doesn’t matter ? Your Prediction: Front Rear Top view of helicopter Your Observation:
0 of 5 Your instructor is standing on a turntable while holding a spinning bicycle wheel. The wheel has angular momentum pointing upward. Your instructor then turns the wheel upside down so the angular momentum points down.What happens to your instructor? Angular Momentum - II • Nothing • He begins to rotate, his angular momentum pointing up • He begins to rotate, his angular momentum pointing down • Need more information Your Prediction: Your Observation:
3 4 2 1 0 of 5 At which point does the satellite have the maximumgravitational force on it? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction:
3 4 2 1 0 of 5 At which point does the satellite have the maximumspeed? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction:
3 4 2 1 0 of 5 At which point does the satellite have the maximummomentum? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction:
3 4 2 1 0 of 5 At which point does the satellite have the maximumkinetic energy? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction:
3 4 2 1 0 of 5 At which point does the satellite have the maximumgravitational potential energy? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction:
3 4 2 1 0 of 5 At which point does the satellite have the maximumtotal energy? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction:
3 4 2 1 0 of 5 At which point does the satellite have the maximumacceleration? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction:
3 4 2 1 0 of 5 At which point does the satellite have the maximumangular momentum? Planet Check Question • 1 • 2 • 3 • 4 • All are the same Your Prediction: