MECE 2304–Dynamics Exam 2 Javier A. Kypuros, Ph.D.
dsYou have 1.5 hours to complete the following exam. Be sure to
read each question carefully and to answer each completely show-
ing all work to recieve full credit. Though you may write on this
handout, only the solutions you submit seperately will be graded.
Thus be sure to note all answers including those for multiple choice
questions on the solutions. Be careful with unit conversions.
Problem 1
(30 points) The roller coaster depicted in the figure is designed so
that riders will experience a force 3 times their weight against the
seat as they reach the bottom of the track. Determine the necessary
radius of curvature if the cars drop from the crest at a speed of 14
ft/s. Neglect friction.
Problem 2
(30 points) A 10-g bullet strikes a 12-kg wooden block on a sloped
surface with an incline angle,
θ
, depicted in the figure. A stopper at
Aprevents the block from sliding down the incline. After impact,
the bullet is embedded in the block, and the block slides up the in-
cline. The kinetic friction coefficient between the block and incline
is
µ
k=0.2. Determine how high the block slides up the incline
after the collision.
Problem 3
(30 points) A quarter and a dime slide on a smooth surface. They
collide, and just before collision they have the velocities depicted
in the figure below. According to the U.S. Mint, a quarter and a
dime have masses of 5.670 g and 2.268 g, respectively. Determine
the velocities (magnitude and direction) of the quarter and dime (in
m/s) just after the collision if the coefficient of restitution, e, is 0.7.
(Note: 1 m = 3.28 ft.)
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