Transcript forces
The Man’s Jeopardy Learning Objectives (Big Ideas) 1. Analyze an object’s motion and be able to determine distance, velocity, speed, or acceleration from a reference point. 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. There are no daily doubles available. Let’s play Motion Forces Work & Energy Machines 100 100 100 100 200 200 200 200 300 300 300 300 400 400 400 500 500 Final Jeopardy Motion for 100 Which of the following describe the object’s velocity: a car going at 60 mph, a truck speeding at -80 mph, and/or a bike traveling at 15 mph South? The truck and the bike examples are velocities because they give the speed & direction (negative & South). Motion for 200 Give an example of when an object has decelerated. Running then slowing down to walking Coming to a stop at a red light. Biking uphill. Motion for 300 Describe an object’s motion if all of the forces acting on the object are balanced & the object is already in motion? What if the forces are unbalanced? Balanced: The object will continue its current motion. Unbalanced Forces: The object would change its motion (such as moving faster or slower or stopping) Motion for 400 In terms of reference points, explain how you could be moving at 60 mph or 0 mph if you were in a car traveling down the road. According to the road or a stationary object on the side of the road, you are moving at 60 mph. However, if the reference point is the car itself, then you are not moving at all. Motion for 500 Determine the object’s average speed over 5 hours from the distance-time graph below. 300 km/5 hours = 60 km/h Forces for 100 Whenever an object is moving on Earth, there will always be ________, which resists the object’s motion in the opposite direction of the net force. Also, on any planet, there will also be _________ which pulls the object down towards the center of the planet. Friction Gravity Forces for 200 Which object would have the greater inertia: a large boulder or a pebble? Which one would have the greater momentum if they are going about the same velocity? Large boulder for both questions (more mass means more inertia and more momentum) Forces for 300 More force is required to make an object ______________ faster or move from rest if it has a large ________. Hint- What affects force? Accelerate faster large Mass Forces for 400 If two track & field stars push with the same amount of force with their legs, which one would accelerate quicker: the heavier runner or the lighter runner? Explain why. Lighter runner because less mass means a quicker acceleration if the force is constant. Forces for 500 Markie & Suzie conduct an experiment to determine how mass affects how quickly objects fall. They choose to drop various objects from the top of a 30 ft. roof. They both believe that heavier objects will fall faster. What is their hypothesis? How should they design the experiment? What is 1 constant? May give answer verbally. Hyp.- Heavier objects fall faster Design- Drop objects of different masses and measure their speed as they fall. Constants- Air resistance, height, dropped the same way, etc. Work & Machines for 100 Machines can make work easier by lowering the applied force, which means the __________ force is greater than the _______ force. Output force (usually the weight or load) is greater than the applied or input force. Work & Machines for 200 A door stopper is an example of a _________ (a type of simple machine), and it has a M.A. ________ than 1 Wedge M.A. greater than 1 Work & Machines for 300 Suppose the input force for an ax splitting wood is 45 N, what would be a possible output force? Any value greater than 45 N, but probably around 90 N or more Work & Machines for 400 For both 1st class (where the fulcrum is closer to the load) and 2nd class levers, how does the load weight compare to the applied force? The load weight is greater than the applied force because both types of levers lower the applied force. Work & Machines for 500 Explain how a wheel and axle machine works in terms of the input vs. output force and input vs. output distance. The input force over the wheel travels a greater distance than the larger output force over the axle. Energy for 100 Which of the following is an example of kinetic energy decreasing: a ball rolling down a ramp, an object in free-fall, or a car going up a mountain road? Car going up the mountain road (slowing down) Energy for 200 For the swinging of a pendulum, where is the PE the greatest and where is the KE the greatest? Draw a labeled diagram to answer this question. Energy for 300 If a skier is going down a mountain, how do the PE and KE change? Explain your answer. PE decreases because the skier is closer to the ground and the KE increases because the skier is getting faster. Gravity If planets A and B are the same mass but planet A is twice as close to Earth as planet B, then which one will Earth have the greatest attraction for? Also, suppose planet C is the same distance from Earth as planet A, but is ¼ as heavy. Now which planet would Earth have the greatest gravitational attraction for? Planet A for both cases because it is closer than planet B, but heavier than planet C.