EXAM 3 December 3, 1997 PHYS 207
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g = 9.8 m/sec2 | Radius of the earth = 6.38 x 106 m | The mass of the electron is 9.11 x 10-31 kg. |
(a). collisions, and (b). equilibrium.(c). How do you recognize that the problem you are working with is a collision problem?
(d) How do you recognize an equilibrium problem?
Principles:
3. (30 points)
F = - [H M m / r] 1r
where H is an experimentally-determined constant.
(a) Show that the speed of a planet in a circular orbit is independent
of the radius r of the orbit.
(b) Show that in such a universe Kepler's third law would take the
form
r / T = constant
where T is the period of the orbit.
Diagram:
Principles:
4. (30 points)
A ring of mass M and radius R lies at rest on its
side on a frictionless table. It is pivoted to the table at its rim.
A bug of mass m starts walking around the ring with speed
v, starting at the pivot. What is the rotational velocity of
the ring when the bug is directly across the ring from the pivot?
Diagram:
Use this page if necessary to continue any of the problems. Be sure to
label the problem number.
A uniform, square sign of mass M, and side h, is
hung from a horizontal rod of length L as shown in the
diagram. A cable is attached to the end of the rod and to a point a
distance W above the point where the rod is fixed to the
wall. What is the tension in the cable and the horizontal and
vertical components of the force exerted by the wall on the rod?
Diagram [complete as necessary]
Imagine a universe in which the law of gravitation has the
inverse-first-power form