Spring 2005
MWF 11:30
Instructor: Dr. Bruce Law, CW
327, Tel: 532-1618.
REVIEW QUESTIONS OF Home Work 8
R26. The force on the can is provided by the
string and is directed along the string towards the center of the circle.
R27. An inward force acts of the clothes and
causes them to go in a circle. In the absence of this force the clothes would
travel in a straight line at constant speed according to Newton`s
first law.
R28. No force. The string provides a force
that acts on the can and causes the can to move in a circular path. In the
absence of this force, according to Newton`s first
law, the can continues to move in a straight line path once the string has
broken.
R29. No force. Your seat belt would have
provided a force on you if you were wearing it, however, as you are not wearing
the seat belt you continue in a straight line path as the car rounds a corner
and consequently slam into the car door.
EXCERISES OF Home Work 8
E38. As the space habitat is rotating, her velocity direction is changing
with time. Therefore, she is accelerating and hence a net force is acting on
her according to Newton 2, F(net) = ma. This net
force, or centripetal force, is pointing towards the axis of rotation. If there
was no net force, she would continue to move in a straight line (Newton 1). The
centripetal force, which is caused by the outer walls of the habitat, makes her
move in a circle and it feels as though she is being pulled by artificial
gravity towards the outer wall.