PHYSICS CHAPTER 7 SECTION 1 Worksheet 2
NAME
1.
PERIOD
A coiled spring is stretched .025 meters by a mass of 20 grams that is hung from one end. How far will a mass weighing 45
grams stretch it? (Answer .0563 m)
F2
F1
d1
2.
d2
The hook of a spring balance is pulled down 3 cm by a fish having a mass of .15 kg. How far will the spring balance move if
a fish with a mass of .27 kg were placed on the same spring balance? (Answer 5.4 cm)
F2
F1
d1
3.
d2
An 8.00-kg mass is supported by a steel wire whose diameter is .80 mm and whose length is 1.50 m. How much will the
wire stretch under this load? (Answer 1.17 mm)
1.5 m long
diam = .8 mm
8 kg
4.
A piece of copper wire was used to suspend a neon sign in front of a store. The diameter of the copper wire was 1.22 mm.
The sign had a mass of 15 kg. A) Determine the tensile strength (stress) of the wire. B) Determine strain of the wire. C)
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2
Was the wire able to hold the sign? (Answer 1.26 X 10 N/m , 1.09 x 10-3, yes)
Pepsi
5.
A steel cable whose effective cross section is 1.20 cm2 supports a 200-kg elevator. When the elevator is at rest at the second
floor the length of the supporting cable is 40.000 meters. What would be the length of the cable if it were not under stress?
(Answer 39.99967 m)
Length = 40
Area = 1.2 cm2
200 kg
PHYSICS CHAPTER 7 SECTION 1 Worksheet 2
6.
A steel rod is used to support a mass of 300 kg. This rod has a length of 2.00 meters and should change its length under load
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by no more than .20 mm. What must the minimum diameter be? (Answer 1.368 X 10 m)
7.
A steel wire can withstand a tensile stress of 5 X 10 N/m . If such a wire is to be used to support a mass of 600 kg, what is
the minimum diameter wire that can be used? (Answer .00387 m)
8.
A nylon line (Y = 8 X 10 N/m ) 10.00 meters in length and 2.00 mm in diameter is subjected to a tension of 30 Newton’s.
Calculate the length of line, neglecting the change in the line's cross section.
(Answer 1.194 m)
9.
A wire of length 2-meter and a cross sectional area 0.1-cm of support a load of 102 kg. The wire is stretched by 0.22 cm.
Find the tensile stress, tensile strain, and Young's modulus for the wire from this information.
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2
-3
10
2
(Answer 1.0 X 10 N/m , 1.1 X 10 , 9.1 X 10 N/m )
10.
You work for DUSEL (Deep Underground Science and Engineering Laboratory). They are rebuilding the number 6 winze.
The engineers need to know the range of diameters for both the minimum and maximum values for steel for this underground
elevator. The winze must be able to move 55 tons from the 4550 level to the 8000 foot level. At the moment they are not
concerned about stretching of the cable. (Answer 4.46cm minimum to 4.77 cm maximum)
11.
The DUSEL engineers have decided to go with at least the larger diameter from the above problem. Now they need a
calculation concerning the stretching of the cable. They would like to know the minimum diameter that is needed to ensure
the cable does not stretch more than 3 feet in the entire length of the 3450 foot shaft. (Answer 6 cm)
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2
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