## Chapter 2: Motion and its Causes

 Describe Newton's Laws and their applications to motion. Given F=ma, calculate the motion of an object If a 5 kg object is acted upon by a force of 20 N, what is its acceleration? If it starts from rest, what will be its speed after 3 seconds? What is the difference between mass and weight? If and object has a mass of 2 kg, what is its weight under normal Earth gravity? If a crate weighs 120 pounds, what is its mass? Describe static and kinetic friction and their applications If the coefficient of static friction of a surface is 0.5 and the coefficient of kinetic friction is 0.4, then how much force will be required to set in motion a 40 kg crate? How much force will be required to keep it going at a constant velocity a after starting? If a large truck and a Volkswagen collide, which is acted upon by the larger force? If more than one force acts on an object, how do you predict its motion from Newton's second law? If a 10 kg object falls in the Earth's gravity but is acted upon by a 40 N air resistance force, what will be its acceleration? Does motion in a circle at a constant speed involve an acceleration? What is the difference between centrifugal force and centripetal force? Which can you measure with a scale? Calculate the centripetal force on an object moving in a curved path, given the mass, velocity, and radius of curvature of the path. If a Ferris wheel ride has a diameter of 20 meters and a speed of 8 m/s, what is the centripetal acceleration of a rider? What is the centripetal force on a 70 kg rider? Why do you feel lighter at the top of the ride and heavier at the bottom? How does the force of gravity change with distance? If an object weighs 600 N at the Earth's surface, what will it weigh twice as far out from the Earth's center? ...three times as far out? What causes the tides? Why are there two per day instead of just one? What is torque? How can you increase the torque on a wrench to turn a stubborn bolt? What is required for equilibrium of a large object? Why do you pick up a long board at it's center? Why is it difficult to lift it by one end alone? Why does a skater spin faster if they pull their legs and arms in? What is the difference between centrifugal force and centripetal force? Which can you measure with a scale? *Motion Concepts *Newton's Laws *F = ma *Mass and Weight *Elevator Problem *Application of F=ma *Motion calculation *Weight calculation *Friction *Force to overcome friction *Newton's 3rd Law *Combinations of forces *Centripetal acceleration *Vector velocities *Centripetal force calculation *Law of gravity *Inverse square law *Circular orbit *Gravity in orbit *Tides *Sun Tide *Jupiter effect *Syncom satellites *Torque *Equilibrium *Force combination *Lifting example *Conservation of angular momentum *Centripetal force *Centrifugal force *Coriolis force
Index
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