Question
igy, which is less than your part B OnServed, or is something else going on? Where are the "missing" joules? IV. Ramp vs. straight up A lazy professor wants to lift a cart from the floor onto a table. He-- can either lift it straight up along path 1, or he can push it up the 1 ramp along path 2 (see the dashed lines in the diagram). If he chooses path 2, the cart rolls with negligible friction. Whichever -RI path he chooses, the cart starts at rest on the floor and ends at rest on the table. Here's the issue: Along which path will the professor do less work on the cart? A. Why might a smart student say the professor does less work lifting the cart along path 1? Why might a smart student say the professor does less work pushing the cart along path 2? might a smart student say the professor does less work pushing the cart along path 2 B. Along which path, if either, does the professor do less work? Hint: Think about the connection between work and potential energy (in cases where the object gains no kinetic energy) C. Reconcile your part C answer with the arguments given in parts A and/or B. In other words, show how elements of the "incorrect" ideas from parts A and/or B can be used to correctly explain why your part C answer makes intuitive sense. Continue on back if needed. D. HW7-2 O University of Maryland Physics Education Research Group, Fall 2004
Explanation / Answer
a since the travel path is short
b since the elevation angel is low
c PE = mgh in both cases
work done in path 1 = mgh
work done in path 2 = mghsin?
since ? is 0 to 90 work in 2 is lesser than 1
d) tavel path is vertical though it is short
