QN (See Giancoli Ch. 5 #7).  What is the maximum speed with which a
<eqn $m = randnum(900, 1200, 50);>kg car can round a turn of radius
<eqn $r = randnum(65, 100, 5);>m on a flat road if the coefficient of
friction between tires and road is
<eqn $mu = randnum(0.70, 0.90, 0.02);>?<_>m/s

<eqn $v = sqrt($mu * 9.8 * $r); &threefigs($v);>

QN (See Giancoli Ch. 5 #14).
How many revolutions per minute would a <eqn $d = randnum(13,18,1);>m
diameter Ferris wheel need to make for the passengers to feel
"weightless" at the topmost point of the trip?
<eqn $r = $d/2.0;
    $v = sqrt($r * 9.8);
    $T = 2.0 * $pi * $r / $v;
    $f = 1.0 / $T;
    # Convert to rev/min
    $f = $f * 60.0;
    # Return empty string
    ""; >
<_>? rev/min

<eqn &threefigs($f);>

QN (See GIancoli Ch. 5 #18).
In a "Rotor-ride" at a carnival, people pay money to be rotated in a
vertical cylindrically walled "room" (see Fig. 5-36, pg. 141).
If the room radius is <eqn $r = randnum(4.0, 6.0, 0.1);>m and the
rotation frequency is <eqn $f = randnum(0.40, 0.60, 0.02);>
revolutions per second when the floor drops out, what is the minimum
coefficient of static friction so that the people will not slip down?
<_>?
<I>Hint</I>: You need to draw a careful free-body diagram here.

<eqn $v = 2.0 * $pi * $r * $f; $mu = 9.8 * $r / ($v * $v); &threefigs($mu);>

#<HR>The next four questions refer to the following
<A HREF="http://workbench.lafayette.edu/~doughera/phys111/ps04s1.html">
simulation</A>.  Run the simulation and print out and fill in the
appropriate blanks in the worksheet.  Then come back to this page
and fill in the next four questions.

QN What is the x-component of the acceleration at t=48?

0
1e-6

QN What is the y-component of the acceleration at t=48?

-0.1605

QN What is the <STRONG>magnitude</STRONG> of the acceleration at t=48?

0.1605

QN What is the <STRONG>direction</STRONG> (in degrees) of the
acceleration at t=48?

<eqn $thisanswer = 270 ? -90 : $thisanswer; -90.0;>