Download PHYS 110

‫جامعة الملك عبدالعزيز‬
KING ABDULAZIZ UNIVERSITY
PHYS 110
Ch. 8
Potential Energy and
Conservation of Energy
Physics Department
Chapter 8
Chapter Eight
Potential Energy and
Conservation of Energy
2

Work and Potential Energy

Conservation of Mechanical Energy

Work Done on a system by an
External Force

Conservation of Energy
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Work and Potential Energy
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Physics Department
Work and Potential Energy
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Physics Department
Work and Potential Energy
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Physics Department
Work and Potential Energy
Example 1 :
A force F causes the 2 kg box to slide up from point A to
point B. The gravitational potential energy gained by the
box is:
Solution:
(A)
(A) 35.28 J
(B) 28.40 J
(C) 88 J
(D) 270 J
B
A
F
6
5.6 m
1.8 m
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Conservation of Mech. Energy
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Physics Department
Conservation of Mech. Energy
Example 2:
In a sliding game at a fun fair, a child train was sliding in
different heights. If the train slipped from height A 10 m till
height B 7 m. The speed of the train at point B is
Solution:
(C)
(A) 10.3 m/s
(B) 9.87 m/s
(C) 7.67 m/s
(D) 6.42 m/s
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Work Done on Sys. by an Ext. Force
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Work Done on Sys. by an Ext. Force
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Physics Department
Work Done on Sys. by an Ext. Force
Example 3:
A car of mass 2000 kg moving on a rough road at speeds of
25 m/s, and then begins to slow down till it’s stop after
200 m. The frictional force that caused the car to stop is:
Solution:
(B)
(A) 2456 N
(B) 3125 N
(C) 5620 N
(D) 7435 N
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Conservation of Energy
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