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Homework Help: Momentum help

  1. Oct 26, 2004 #1
    i need help on how to start to solve part c in a 3 part question. the question reads "Jerry is stationary on his skateboard at the top of the hill shown in the following diagram. he than rolls from rest down the hill. A) assuming that the hill provides a frictionless surface, determine jerry's speed at the bottom of the hill.
    B)when Jarry reaches the horizontal surface near the bottom of the hill, he jumps off the skateboard so that he ends up moving 5.8m/s in the orginal direction of the skatebaord. what is the resulting velocity of the skateboard?
    C)how much work does jerry do on the skateboard in order to jump off?" the diagram is that jerry is sitting at the top of the hill it sort of looks like this
    l \
    l \
    l \
    with 2.2m along the vertical and 5.0m along the horizontal. jerry's mass is 40.0kg and the skatebord's mass is 3.0kg.
    for part A) i got jerrys speed as 6.57m/s. part B) i got the velocity of the skatebord as 16.8m/s east. know i know the formula to find work is w=fd. but i don't have a force i guess i could figure that out but what would i use for the distance. or if any body has a better suggestion on how to solve this problem would be a great help. thanks.
    Last edited: Oct 26, 2004
  2. jcsd
  3. Oct 27, 2004 #2


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    Homework Helper

    There is more than one way to find the work done. Remember the Work-Energy Theorem. Ask yourself - where does the work Jerry does go?
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