1–15.Two boys find that they can balanceeach other on a plank if one sitssix feet from the fulcrum and theother eight feet.The heavier boyweighs 120 pounds.How much doesthe lighter boy weigh?1.90 lb2.106 lb3.112 lb4.114 lb1–16.With the aid ofshown in figurethe1D,pipe wrenchhow many poundsof effort will you need to exert toovercome a resistance of 900pounds?1.25 lb2.50 lb3.75 lb4.100 lbQuestions 1-17 and 1–18 are relatedoto a 300–pound load of firebrickstacked on a wheelbarrow.Assume that theweight of the firebrick is centered at apoint and the barrow axle is 1 1/2 feetforward of the point.1–17.1-18.1-19.If a Seaman grips the barrowhandles at a distance of three feetfrom the point, how many totalpounds will the Seaman have to liftto move the barrow?1.65 lb2.100 lb3.150 lb4.300 lbIf a Seaman grasps the handles3 1/2 feet from the point where theweight is centered, how many poundsof effort will be exerted?1.50 lb2.90 lb3.100 lb4.120 lbIn lever problems, the length ofthe effort arm multiplied by theeffort is equal to the length ofthe1.resistance arm multiplied bythe effort2.resistance arm multiplied bythe resistance3.effort arm multiplied by theresistance arm4.effort arm multiplied by theresistance1-20.The length of the effort arm infigure 1E is equal to the length ofthe1.curved line from A to C2.curved line from A to D3.straight line from B to C4.straight line from B to D3