Introduction to Vectors

iiiliiitiiiiiiiilli !F!=0llvilil iillll iiiilllllvilliiliiiiitiiiliiis ilLast Lecture Introducton Today Force as a vector Statc equbrum Addon and subtracton on vectors Important Concepts Force s a vector, both magntude and drecton matter Vectors: Thnk wth arrows, cacuate wth components Probem Song Too: Settng up Make a carefudrawng Thnk carefuy about aof the forces Chose an axs, put t on your drawng Thnk carefuy about the anges Probem Song Too: Component checkst Loop through vectors, s there a component? Is there an ange factor Is s sne or cosne? Is t posve or negatve? Important Announcement If you, or anyone you know was advsed that you shoud not take both 8.01L and 18.01A now because they cannot take 8.01L and 18.02A n IAP: THIS IS WRONG!! Many, many students have taken 8.01L and 18.02A durng IAP. Ths NOT a probem. “” iiiiiilliiltiiil jltiply ltiiil illall iiiiiChalkboardOutline What s a vector? How do you descrbe a vector? How do you add and subtract vectors? What does ths have to do wth forces? Basic idea behind components Want to do a quanttatve cacuaton wth vectors Need to convert mu-dmensonaobect to numbers, add or subtract or muthe numbers, and then generate the mu-dmensonaanswer Wrte each vector as a sum of smaer sub-vectors, of whch pont n the same drecton. F1 F2 F3 Does it move? 1… X Y XY Think with arrowsCalculate with components -version 1 Calculate with components -version 1 2 XY 2 XY Y X iiiiiiiiilliis Fiiiiiliiil () iCalculate with components -version Calculate with components -version Summary Vector: Any quantty characterzed by both a magntude and drecton. Addng or subtractng vectors: Thnk wth arrows, cacuate wth components. Force a vector. rst crteron for statc equbrum s that the totaforce added as vectorss zero. 2