Information for items 2–44 through@2–46:YOU are using a first–classlever to raise a 400–pound load to aheight of 1 foot.The effort arm of yourlever is 8 feet long and the resistancearm is 2 feet long.2–44.How much work is done in raisingthe load?1.400 ft–lb2.300 ft–lb3.200 ft–lb4.50 ft–lb2–45.How far must you move the lever inorder to raise the load 1 foot?1.1 ft2.2 ft3.8 ft4.4 ft2-46.How much work is done in balancingthe load at the 1-foot height?1.0 ft–lb2.2 ft–lb3.8 ft–lb4.10 ft–lb2–47.By using a machine to move anobject you can1.decrease the amount of work tobe done2.reduce the weight of the object3.decrease the amount of theeffort required4.reduce the resistance of theobjectInformation for questions 2–48othrough 2–51:You are using a24,000–pound load with a screwjack thathas a pitch of 1/4 inch and a 24-inchhandle.2–48.Theoretically, (by neglectingfriction),you should be able toturn the jack handle by exerting aneffort of about1.24 lb2.40 lb3.60 lb4.80 lb2-49.Because of friction. you actuallyhave to apply a 120–pound force toturn the jack handle.About howmuch work do you do in turning thehandle one complete revolution?1.120 ft–lb2.240 ft–lb3.1,500 ft–lb4.3,000 ft–lb2–50.With each revolution of the jackhandle, the work output of the jackequals1.100 ft-lb2.200 ft-lb3.500 ft–lb4.600 ft–lb2–51.The efficiency of the jack is1.12 1/2%2.33 1/3%3. 50%4.66 2/3%Information for questions 2–52othrough 2–54:You push with aforce of 125 pounds to slide a 250–poundcrate up a gangplank.The gangplank is 12feet long and the upper end is 5 feetabove2–52.2-53.2-54.the lower end.What is the theoretical mechanicaladvantage of the gangplank?1. 12. 23. 2.44.12How much of your 125–pound push isused to overcome friction?1. 21lb2.42lb3.62 1/2 lb4.125lbWhat is the efficiency of thegangplank?1.25%2.50%3.75%4.83.3%18
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