Transcript forces
The Man’s Jeopardy Learning Objectives (Big Ideas) 1. Analyze an object’s motion and be able to determine distance, instant & average speed, or acceleration. 2. Describe how the various balanced and unbalanced forces can have an effect on an object’s motion. 3. Apply Newton’s Laws to real world examples. 4. Analyze the methods by which machines make work easier. 5. Examine situations where kinetic energy is changed into potential energy (and vice-versa). RULES 1. There will be round robin play and all questions will be all-play. 2. The teams who answers correctly win the point value of the question. 3. If a team answers a daily double incorrectly, then that team will lose the number of points they bid. 4. There are no daily doubles available. Let’s play Motion Forces Work & Energy Machines 100 100 100 200 200 200 300 300 300 400 400 400 500 500 500 300 Final Jeopardy Motion for 100 What is the distance traveled at the 4 s mark? 40 m (+ or – 2 m) Motion for 200 Draw a distance-time graph for an object that is not moving at all. Straight horizontal line on a distance vs. time graph Motion for 300 Draw a speed-time graph for an object traveling at a constant speed. Graph should be a straight horizontal line indicating the same speed over a period of time for a speed-time graph. Motion for 400 Draw a distance-time graph for an object traveling at a constant speed. Graph should be a straight line slanted up and to the right or down and to the right (with distance on the y-axis and time on the x-axis) Motion for 500 Draw a speed-time graph showing an object slowing down. Graph should be a slanted line going down and to the right on a speed-time graph. Forces for 100 Which of the following would exert the greatest force: a truck accelerating at 5 m/s/s, a small stone accelerating at 6 m/s/s, or a person accelerating at 5.5 m/s/s. Explain your answer. The truck because its greater mass has a greater effect on the force it would exert than the slightly higher accelerations of the person and the stone. Forces for 200 Explain why a person can sometimes fly backward when kicking another person. Hint- Newton’s 3rd Law. The action force is the kick, while the equal and opposite reaction is the body of the person who’s being kicked pushing back on the kicker. Forces for 300 Why are larger people unable to move as quickly as lighter people? More force is required to accelerate a heavier mass. Forces for 400 Explain why your body moves backward when a car first takes off. Your body is at rest and attempts to remain at rest (due to your inertia). Forces for 500 Markie & Suzie conduct an experiment to determine how mass affects the force exerted by an object. They choose to accelerate objects down a ramp. They both believe that heavier objects will exert more force. What is their hypothesis? What is the independent variable? What is the dependent variable? What are 2 constants? Hyp.- Heavier objects exert more force Ind. Var.- Mass of the objects Dep. Var.- Force exerted Constants- Same ramp height/incline, same acceleration, same object, same position of release on the ramp Work & Machines for 100 Which class of lever is the input force opposite the output force? Is this the class that pliers belong to? 1st class Yes, b/c the fulcrum is in the middle. Work & Machines for 200 How can you increase the M.A. of a pulley system? Add more pulleys to create more sections of rope. Work & Machines for 300 Suppose the input force for a screwdriver is 15 N, then which of the following could be the output force: 0 N, 10 N, 15 N, or 30 N? Also, how does the M.A. compare to 1? 30 N (output is greater than input, M.A. > 1) Work & Machines for 400 Which of the following would be the best example of a compound machine: scissors, ruler, wheelbarrow, or door stopper? List 2 types of simple machines that make up the compound machine. Wheelbarrow: wheel & axle and lever (2nd class) Work & Machines for 500 Explain how a screwdriver works. The input force over the wheel (handle) travels a greater distance than the larger output force over the axle (metal rod). Energy for 300 If your throw a ball up in the air, how do the PE and KE change as the ball goes up and then comes back down? Explain your answer. PE increases as the ball goes up because it is higher off of the ground while the KE decreases until the ball starts to gain speed as it goes back toward the ground. As the ball goes down, the KE increases and the PE decreases (lower height). Forces Newton’s Cradle demonstrates how momentum (and energy) can be transferred between objects. However, after a period of time, the metal spheres do not bounce as high and eventually stop moving. Explain why this occurs. Friction between the spheres as well as the air around the cradle cause the momentum and energy to be “lost”.