A girl pulls a wagon with constant velocity along a level path for a distance of 45 m. The handle of the wagon makes an angle of 20.0 degrees with the horizontal and she exerts a force of 85 N on the handle. Find the amount of work the girl does in pulling the wagon?
I know the answer should be 3.6*10^3 J but i dont know how to get this, please help.
2007-01-09 06:04:28 · 2 answers · asked by dreamz 4 in Science & Mathematics ➔ Physics
Only the horizontal force contributes to the work. Using the 20 degree angle, Fx = 85 x cos(20) = 79.874N
work = force x distance = 79.874 x 45 = 3.6x10^3
2007-01-09 06:16:46 · answer #1 · answered by Leonardo D 3 · 1⤊ 0⤋
Poor girl.
Work = Horizontal Force (F) time Distance(D)
F=Fgirl Cos (20)
so
W=F D=
W=Fgirl Cos (20) D
W=85N Cos (20) 45m=
W=3595 Joules
2007-01-09 06:16:31 · answer #2 · answered by Edward 7 · 1⤊ 0⤋