Simple Harmonic Motion Quiz B
D
E
1. In the diagram to the right, a block is
attached to a Hookean spring. The spring
is neither stretched nor compressed at
position C. Assume that frictional effects
are negligible. The velocity vs. time
graph below represents the motion of the O-
block as it oscillates between positions A
and E. Fill in the boxes with the correct
0
positions corresponding to the graph shown. On the axes indicated, sketch the corresponding
position, acceleration, force, kinetic energy, elastic energy, and total energy vs. time graphs.
U
velocity
time
time
acceleration position
time

The us government wants to allocate billions of dollars in the next 10 years to assure our future energy security. the funds will be spread among a variety of possible energy resources. where do you think the government should put the greatest support: solar energy, wind energy, clean coal, oil exploration, gas exploration, or a combination of sources? are there other efforts that should be explored? support your position with cited information for both questions.

Part f - example: finding two forces (part i) two dimensional dynamics often involves solving for two unknown quantities in two separate equations describing the total force. the block in (figure 1) has a mass m=10kg and is being pulled by a force f on a table with coefficient of static friction îľs=0.3. four forces act on it: the applied force f (directed î¸=30â above the horizontal). the force of gravity fg=mg (directly down, where g=9.8m/s2). the normal force n (directly up). the force of static friction fs (directly left, opposing any potential motion). if we want to find the size of the force necessary to just barely overcome static friction (in which case fs=îľsn), we use the condition that the sum of the forces in both directions must be 0. using some basic trigonometry, we can write this condition out for the forces in both the horizontal and vertical directions, respectively, as: fcosî¸â’îľsn=0 fsinî¸+nâ’mg=0 in order to find the magnitude of force f, we have to solve a system of two equations with both f and the normal force n unknown. use the methods we have learned to find an expression for f in terms of m, g, î¸, and îľs (no n).

A51 kg woman skis down a hill and her kinetic energy is 9.96e4 j. what is her speed?