2Problem 1.42Vector A has components Ax=1.30 cm and Ay= 2.25 cm; vector B has components Bx=4.10 cm, By=-3.75 cm. FindThe components of the vector sum A+Bthe magnitude and direction of A+BThe components of the vector B-AThe magnitude and direction of B-A
3The components of the vector sum A+B The sum of the x-components of A and B are equal to the x component of A+B
13Problem 1.61Biological tissues are typically made up of 98% water. Given that the density of water is 1 x 103 kg/m3, estimate the mass ofthe heart of an adult humana cell with a diameter of 0.5 mm.a honey bee.
14Best guessesHuman heart: size of fist (cylinder 4” long with diameter of 3”)Honey bee: 1” or 2.5 cm long cylinder with 0.25” diameter
15Heart Problem 4” = 4*2.54 cm = 10.16 cm or 0.1016 m Volume of cylinder= p*(d/2)2 *Lp * (7.62/2)2 *10.16=463 cm3 or ccNote: kg =1 pound
16Book answer differs by order of magnitude A cellAssume spherical!Volume=4*p/3*(d/2)3Book answer differs by order of magnitude
17Honey beeV=p*(d/2)2 *L=p*(.25/2)2 *1=0.049 in3Book assumes ½ in long
18Problem 1.70A sailor in a small sailboat encounters shifting winds. She sails 2.0 km east then 3.5 km southeast (-450 w.r.t. east) and then an unknown distance. Her final position is 5.8 km directly east of starting point. Find magnitude and direction of the third leg of the journey.