Forces and Motion Unit 1. 2. Learning Goals We will re-visit Newton’s First Law Success Criteria I know that an object will travel in straight line at a constant speed unless there is a net force acting on the object We will re-visit Newton’s Second Law I can apply the First Law to explain various situations I know that objects that are heavier typically will accelerate less when there is a net force acting on it, compared to lighter objects I can apply the Second Law to explain various situations I can explain what net force means, and know how to calculate it I can explain the difference between balanced and unbalanced forces 3. We will analyze the forces in 2 dimensions acting on objects that are at rest and accelerating I can complete the practice problems related to this learning goal I can draw the forces acting on an object I can find the components of a force acting at an angle with respect to the horizontal using cosine and sine ratios I can determine the normal force acting on an object while it is accelerating, or if there is more then the force of gravity acting on it (that is, if there is an applied force acting partially in the horizontal direction and partially in the vertical direction) I can solve for the acceleration of an object, if the forces are known I can solve for the forces acting on an object, if the acceleration is known or can be solved for 4. We will analyze the forces in 2 dimension acting on an object moving down an incline (hill) or up an incline I can complete the practice problems related to this learning goal I can draw the forces acting on an object while sliding down on an incline or going up an incline I can find the components of the force of gravity acting on an object I can draw the normal force acting on an object (normal means ___________ to the surface) I can solve for the acceleration of an object on an incline, if the forces are known I can solve for the forces acting on an object on an incline, if the acceleration is known or can be solved for 5. We will investigate the force of friction and the coefficient of friction, both static and kinetic I can complete the practice problems related to this learning goal I can draw the force of friction acting on an object I can solve for the force of friction if the coefficient of friction and the normal force is known I can solve for the coefficient of friction (both static and kinetic) by performing an experiment I can complete the practice problems related to this learning goal 6. 7. We will analyze the force of friction for objects that are moving on a plane and for object that are moving on an incline We will re-visit Newton’s Third Law I understand that without friction, a car would not be able to accelerate (either speed up or slow down) I understand that reducing friction is important for some sporting activities I can solve for the force of friction, if the acceleration and all other factors are known I can complete the practice problems related to this learning goal I can apply the Third Law to explain various situations I understand that when objects are connected by a cable, the force of tension acting on each object is identical 8. 9. 10. We will analyze the forces acting on a pulley system in a variety of situations (when accelerating and when at rest) We will analyze circular motion and the formulas that are used to calculate centripetal acceleration We will analyze the forces that are acting on objects while experiencing a centripetal acceleration. These situations include the forces acting on a car that is turning, forces acting on a ball at the end of a string while turning and the forces acting on a pilot while flying a plane I can complete the practice problems related to this learning goal I can draw the forces acting in a pulley system I can solve for the acceleration of a pulley system if I have knowledge of all the forces acting on the pulley system, by using a system of equations I can solve for the force of tension in a pulley system I can complete the practice problems related to this learning goal I can solve for the speed of an object traveling in a circle if given the object’s radius and period I can solve for the centripetal acceleration of an object based on being given the object speed, period and/or radius I can complete the practice problems related to this learning goal I understand that for an object to travel in a circular parth (orbit), it requires a force acting towards the center of the circular path I can draw the forces acting on a car during a turn I can solve the centripetal acceleration of a car if I have knowledge of the forces acting on the car I can solve for the maximum force of friction required to complete a turn by a car based on the speed of the car and its turning radius I can draw the forces acting on a ball attached to a string while spinning in a horizontal or vertical plane I can solve for the tension force acting on a ball attached to a string while spinning in a horizontal or vertical plane I can extend my understanding of centripetal forces to analyze problems beyond those presented during class time (see practice problems) 11. 12. We will analyze the advantages of a clothoid loop We will analyze the forces acting on a car I can explain what a G-Force is and how a G-suit helps fighter pilots and possibly prevents them from blacking out I can explain why some roller coasters use loops that are shaped like a clothoid instead of a circle, using ideas related to centripetal forces I can draw the forces acting on a bank curve for a car and find the components of force of friction and the normal force that is turning on a banked angle, and the advantages offered by a banked angle I can solve problems related to bank curves (determine maximum centripetal acceleration) Using the ideas of forces, I can explain why bank curves are used for highway exit or entrance ramps 13. We will analyze the force of gravity acting between objects that are separated by large distances (ie a satellite and a planet, or a planet and its moon) I can complete the practice problems related to this learning goal I understand how to apply Newton’s Universal Law of Gravitation I understand when I am near the surface of a planet, F = mg is the same as the Universal Law of Gravitation I understand the relationship between gravitational force of attraction and distance I understand the relationship between gravitational force of attraction and mass I can solve for the force of gravity acting between two objects if I know the object’s mass and the separation distance 14. We will analyze orbital mechanics and the force acting on objects in orbit I can complete the practice problems related to this learning goal I understand that for an object to maintain a circular orbit, the object requires __________________ and ___________________ I can draw the forces acting on an object while in orbit I can solve for the orbital period of an object if I know the distance the object is from a planet along with the planet’s mass 15. 16. 17. We will investigate centripetal forces using video analysis of a toy We will investigate centripetal forces and use the theory to predict the mass of an object that is spinning We will investigate the motion of falling coffee filters and examine the forces acting on them at terminal velocity I can complete the practice problems related to this learning goal I can apply my understanding of bank curves to help solve other problems (ie spinning toys) I can complete a lab experiment and by measuring the period and radius for a rubber stopper that is spinning, along with indirectly measuring the centripetal force, I can determine its mass I can determine the terminal velocity for a falling object using its fall distance and a stopwatch to record time I can measure the drag force acting on a falling object when it is at terminal velocity, by knowing the mass of the object I can determine the coefficient of drag by creating a graph (see lab instructions), drawing a line of best fit and calculating the slope for the line of best fit