Regular Physics Chapter 4 Concept Development Page 1116

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Regular PhysicsChapter 4Concept
DevelopmentPage 11-16

• Created for CVCA Physics
• By
• Dick Heckathorn
• 19 October 2K4

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Table of Contents CD

• 3 Statics p-11
• 6 Vectors Equilibrium p-12
• 11 Force and Velocity Vectors p-13
• 14 Vectors and Equilibrium p-14
• 19 Force and Velocity Vectors p-15
• 22 Net Force p-16

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1. An astronaut in outer space away from all
forces throws a rock. What will happen to the
rock?
The rocks tendency to do this is called
inertia.
What is inertia?
How is it measured?
grams /kg.
CD p11
4
2. The rock is being whirled at the end of a
string in a clockwise rotation.
What is the path of the rock when the string
breaks?
A
B
C
C
D
CD p11
5
3. The bus is traveling at 100 km/h.
Relative to the bus, the pencil is traveling at
Its horizontal velocity is
100 km/h.
0 km/h.
As it drops, its horizontal velocity is
100 km/h.
Where will the pencil strike the floor?
Where will the pencil strike the floor if the bus
is at rest?
Directly below where dropped.
Directly below where dropped.
CD p11
6
4. The force due to gravity on an object is
called?
weight
The quantity of matter in an object is
called?
mass
The amount of space an object occupies is
called?
volume
CD p12
7
5. The force due to gravity on 1-kg is
w mg
9.8 N
The force due to gravity on 5-kg is
49 N
The mass with a weight of 98 N is
10 kg
CD p12
8
Find g on moon

• Click to show video clip of dropping hammer on
  the moon.
• Determine t and d and then find g using d
  ½ gt2.

Click
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6. Find the weight of your physics book. Then
complete the table.
9.8 N
0.1 kg
882 N
CD p12
10
7. Hit lead plate with hammer
CD p12
11
300
300
150
300
CD p13
12
300
150
No!!!
100
300
150
No!!!
CD p13
13
500
830
1000
CD p13
14
The rock hangs at rest.
T
Fs on r
The net force on the rock is
What force(s) act on it?
How do they compare?
Zero.
W
Fe on r
CD p14
CD p14
15
The rock is suspended by two strings.
B
A
E
There is a tension in each string.
FB on r
FA on r
How big is each tension?
Fe on r
W
The net force is
0
CD p14
16
What is different here?
E
The angles are different.
A
Find the magnitude of A and B.
B
W
Fe on r
CD p14
17
E
B
A
The tension is greater in A or B?
Fe on r
W
CD p14
18
B
A
Fe on r
B
A
Fe on r
A
B
Fe on r
CD p14
CD p14
19
Force Vectors
CD p15
20
Force Vectors
Velocity Vectors
CD p15
21
The forces on the ball are?
CD p15
22
4
0
Fnet
4
1
Fnet
3
4
CD p16
23
4
4
3
5
Fnet
Fnet
5
3
4
2
4
2
5
3
3
Fnet
5
Fnet
5
5
CD p16
24
9.9
9.9
7
0
CD p16
25
Thats all folks!