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stoich
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Homework Statement
Basically, Alice is pushing her brother Jeff on a toboggan at an ice skating rink that is flat except for a ramp that has an incline of 30 degrees
Alice weighs: 60 kg
Jeff weighs: 28 kg
Toboggan weighs: 2 kg
They decide to push Jeff and the toboggan up the ramp. They start from rest 10 m from the incline and she pushes him with a force that varies with the distance [the book has a figure of Force (N) vs. Distance (m)]. You can see the diagram if you google the question below.
http://books.google.ca/books?id=HCU... she lets go just before the incline?&f=false
Jeff goes speeding up the incline with a velocity of 2 m/s
The Question is:
"How much work does Alice do from the moment she begins to push Jeff 10 m from the incline until she let's go just before the incline?"
A) 60J
B) 75J
C) 0J
D) There is not enough information to answer the question
Homework Equations
I know how to solve the problem, I realize Figure 1: Force vs. Distance graph will give me the amount of work applied if I add the area under the graph. The problem is the graph doesn't show the Force and I am not sure how to solve for it.
F=ma
Vf^2=Vi^2 +2ad
a= Vf^2/d
The Attempt at a Solution
I figure the mass is the Toboggan + Jeff.
But solving for acceleration is the problem I am having. I know the initial velocity will equal to zero, but the velocity during the distance traveled I cannot figure out
The answer they give for Force = 7.5 N
Any help would be great,
Thank you