- #1

- 2

- 0

## 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 lets 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