Today’s special Hw check – vocab Test results Notes HW for next time: HW I due Newton’s Third Law of Motion PAe.7: Explain the motion of objects on the basis of Newton’s three laws of motion: inertia; the relationship among force, mass, and acceleration; and action and reaction forces. PAa.1: Generate hypotheses on the basis of credible, accurate, and relevant sources of scientific information. PAa.2: Use appropriate laboratory apparatuses, technology, and techniques safely and accurately when conducting a scientific investigation. PAa.9: Use appropriate safety procedures when conducting investigations. Question When a rocket blasts off, if it was not near the ground, would it take off? Newton’s Third Law Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first Simple rule Action: Object A exerts force on object B Reaction: Object B exerts a force on object A Action and reaction Effects on objects differ if their masses are different a = F/m Decreasing mass makes the acceleration greater Action and reaction forces act on different objects Forces cancel only when they act on the same body Donkey cart Equal and opposite? Donkey pulls and cart and pushes on road Bull fights Why are they dangerous? Tug-of-war How does it work? Question When a rocket blasts off, if it was not near the ground, would it take off? Homework Chapter Review HW: pp. 80-82 I. Review questions2-20 even (due date: ____________) II. Exercises 2-20 even; Problems 18 (due date: __________) Today’s special HW check; Q & A Lab Newton’s Laws video Lab due next time! Don’t forget to write your conclusion Today’s special Turn in lab on front table Some equations for HW II Work on HW II with table partner (work on problems, first!) Handout: Newton’s 3rd Law New seating chart Some equations for HW II F=ma a=v/t F1=-F2 Example Billy rides his bike from rest to 8 m/s in 4 s. How much force did Billy apply to his bike if he and his bike have a mass of 75 kg? Example Sally pushes her skateboard with a force of 5 N. The skateboard has a mass of 2 kg. How fast is it going after 3 seconds? Today’s special Student Agenda grade (planner) HW II check Computer project Practice Test on Smartresponse system; enter answers, make corrections before turning in next class Test 4 next time! Today’s special Turn in Practice test on front table Test 4 Newton’s 3rd Law, enter MC answer on smart response Turn in test completed with sentences & essays Get Vocab 5: Momentum; work quietly until everyone has finished their test. Movie time!