Chapter 4: Dynamics, Newton’s LawsSlide 2Slide 3Adding force vectorspulling a sled, Michelangelo’s assistantSlide 6Weight, normal force and a boxSlide 8Unwanted weight loss(descending)Slide 10Slide 11Pulling a boxSlide 13Box sliding downSlide 15Getting the car out of the mudSlide 17Atwood’s MachineSlide 19Slide 20Slide 21Slide 22Slide 23Slide 24Chapter 4: Dynamics, Newton’s LawsFirst Law: Every body stays in its state of motion( rest or uniform speed) unless acted on by a non zero net force.Third Law: Action is equal to reaction.Second Law: The acceleration is directly proportional to the net force and inversely proportional to the mass:mFaAdding force vectorspulling a sled, Michelangelo’s assistantFor forward motion: FAG> FAS FSA > FSGWeight, normal force and a boxUnwanted weight loss(descending)maFPulling a boxNote: FN is less than mgBox sliding downcos0cos mgFmgFmaFNNyysinsin gamamgmaFxxGetting the car out of the mudFT=? a=?Draw a free body diagram for each mass and choose up positive, then a2= a , a1= -aFT - m1g = m1a1= -m1aFT – m2g = m2a2= m2a----------------------------------------------------------------------------------- (m1–m2)g=(m1+m2)a)(1112121agmamgmFgmmmmaTAtwood’s Machine= mass of elevator and loadWork our the acceleration of the system shown if it is pulled up with a force of 200N.Why does the force need to pull the backpack up increase?Precautions in Yosemite ParkWhere does the thread
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