1. How much work must be done to stop a 1000 kg car traveling at 110 km/h? 1 2 1 2 1 2 5 W = KE= mv − mv 0=0− 1000 kg [110 km/h3600 s/h] =−4.67∗10 J. 2 2 2 1. a)Find the force required to give a helicopter of mass M an acceleration of 0.10g upward. F y =ma y : F−Mg=Ma F=M ag=1.10Mg b) Find the work done by this force as the helicopter moves a distance h upward. o W F=Fh cos0 =1.10 Mgh 2. What is the minimum work needed to push a 1000 kg car 300 m up a 17.5-degree incline? y−component : F N −mgcos =0 ; x−component : F min−mgsin =0. for a distance d along the inclie , we have W min =F min d cos 0o −mgdsin =1000 kg9.8 m/ s2 300 m sin17.5 o=8.8×105 J.
© Copyright 2024 ExpyDoc
