AP PHYSICS LARGE GROUP

1
AP PHYSICS LARGE GROUP

• CYCLE 9
• WED., NOVEMBER 23, 2005
• ENERGY

2
THE GREAT CAN RACELARGE GROUP TODAY!!

• SLOWEST VS. FASTEST

3
AP PHYSICS CAN ROLL-OFF
4
Loop the Loop

• Energy Analysis Find speed anywhere in loop

Vo 0
KE gain PEg lost
mgDh
½ mV2
V 2gDh
5
Loop the Loop

• Energy Analysis Find Dh to make the loop.

At Vc
mg is Fc
Vo 0
mg mV2/R
KE critical
Dh
V critical
Vc gR
mg
PEg lost KE top
Dh ½ R
mgDh ½ mVc2
gDh ½ gR
6
LAB 10A Hit the Bull
7
LAB 10A Hit the Bull
ENERGY PROJECTILE MOTION
KE gain PEg lost
½ mVc2 mgDh
Vc 2gDh
8
LAB 10A Hit the Bull
d Vot ½ (at2)
Yo Vot ½ (gt2)
Yo ½ gt2

t 2Yo/g
X Vx t
X
X
2gDh
2Yo/g
2 DhYo
9
LAB 10b SLIDING MASS 2
d
WHAT DETERMINES STOPPING DISTANCE?
WORK DONE BY FRICTION KE LOST
f mmg
f d
½ mV2
mmgd
½ mV2
d independent of MASS
d
V2
d a 1/m
d a 1/g
d a V2
2mg
10
H.W. 9 7-52
Q