Presentation 8 8 8.notebook
What happens if you
exceed the maximum
static friction
between the tire and
road?
December 13, 2012
c
t
2
This equation shows
what is needed.
NOT what is created.
Presentation 8 8 8.notebook
A pail of water is rotated in a vertical circle of radius 1.00 m.
a. What two external forces act on the water in the pail?
b. Which of the two forces is most important in causing the
water to move in a circle?
c. What is the pail's minimum speed at the top of the circle
if no water is to spill out?
d. If the pail with the speed found in part (c) were to
suddenly disappear at the top of the circle describe the
subsequent motion of the water?
December 13, 2012
Presentation 8 8 8.notebook
December 13, 2012
F(N)
F(N)
Universal Law of Gravity
m1 (kg)
F(N)
m2 (kg)
distance (m)
Presentation 8 8 8.notebook
December 13, 2012
Universal Law of Gravity
G
1 2
2
3
G = 6.67 x 10-11 m 2
kg s
7 A ball falls to the ground. Which of the following statements
are false?
A
The force that the ball exerts on Earth is equal in
magnitude to the force that Earth exerts on the ball.
B The ball undergoes the same acceleraƟon as Earth
C
Earth pulls much harder on the ball than the ball pulls
on Earth, so the ball falls while Earth remains staƟonary
Presentation 8 8 8.notebook
December 13, 2012
Three 0.300-kg billiard balls are placed on a table at the
corners of a right triangle, as shown from overhead in the
figure.
a. Find the net gravitational force on the cue ball m1
resulting from the forces exerted by the other two balls.
b. Find the components of the gravitational force on m2
and m3.
Presentation 8 8 8.notebook
December 13, 2012
Gravitational Potential Energy
PEg=mgh
Only works near the
surface of the earth.
Under what
circumstances was
the gravitational
potential energy
negative?