A material's ability to withstand great deformation under high loads
before rupturing is a measure of its:
a. Toughness
b. Ductility
c. Ultimate strength
d. Malleability
a
A cantilever beam:
C.
The term _________ is used as a measure of the quantity of matter.
a. Volume
b. Weight
c. Mass
d. Relative density
c
Relative density of a substance is:
a. The mass of a substance compared to air.
b. The volume of a substance compared to water.
c. The mass of a substance compared to water.
d. None of the above
d
Factors of safety have units.
T or F ?
f
The formula, stress = load divided by the area, can be transposed
to read stress times load when you must solve to find the correct area.
T or F ?
f
A certain chimney is 23m high and is supported by a number of guy wires. Each guy
wire is anchored at 6.9m away from the base of the chimney, and at 18.4m high on the
chimney, in such a way that a right triangle is formed. The material the wires are made
from has an E = 206GPa, an ultimate strength of1260MPa, and each wire has a diameter of
8mm. Considering a factor of safety of 7 calculate:
1) The extra length each wire stretches __________ mm
2) The working stress each wire carries __________ kPa
3) The tensile load each wire carries __________ kN
17.1710
180000
9.0478
A cantilever beam is 4m long and carries a concentrated load of 285kN at its free end.
The beam is also uniformly loaded at19kN/m over its entire length. Calculate the shear
force and bending moment at the wall. Caution: (Give your answers as positive numbers only)
a. __________ kN shear force
b. __________ kN/m bending moment
361.0
1292.0
A body's ability to resist change in shape and size under an applied load is known as:
a. Stiffness
b. Ductility
c. Toughness
d. Malleability
a
The term "concentrated load" refers:
a. Only to loads supported by simple beams
b. Only to loads supported by cantilever beams
c. To loads which act at a single point on a beam
d. To beams in equilibrium
c
Steam under pressure in a boiler has:
a. An area
b. Energy of motion
c. Potential energy
d. Kinetic energy
c
A load carried by a beam will produce bending stress.
T or F ?
t
A load exerted upon rivets produces a tensile stress.
T or F ?
f
. A rod is 12mm in diameter and has a tensile strength of 1140MPa.
If the rod supports a tensile load of 21.49kN, find the safety factor.
5.9996
A beam 8m long, simply supported, has a load of 11kN acting down upon it, 2.4m from the
right hand support. Another load of 20kN is also acting on it 3.2m. from the left hand support.
If R1 is the reaction at the left support and R2 is the reaction at the right support, calculate R1
and R2.
a. R1 = ___________ kN
b. R2 = ___________ kN
a. 15.3
b. 15.7
A mercury manometer at a condenser reads a difference of level between its two legs of
639mm of mercury as vacuum. If the atmospheric pressure at the locality is 100.6 kPa.
Find the absolute pressure in kPa at that condenser. (Take the gravitational constant
g=9.81N/kg, or m/sec².
15.3472 kPa
The term "plasticity" is applied to material which:
a. Is brittle in its composition
b. Is not capable of being reshaped
c. Will return to its original shape after being deformed
d. Will not return to its original shape after being deformed
d
A tensile test is performed by subjecting the specimen to a/an:
a. Charpy test
b. Izod test
c. Brinell test
d. Stretching type load
d
Steam under pressure in a boiler has:
a. An area
b. Energy of motion
c. Potential energy
d. Kinetic energy
c
Breaking load and maximum load are the same thing.
T or F
f
A _______ beam has one fixed end and one free end.
Cantilever
The diameter of the drum of a winch is 56cm. The drum is rotated at 120rpm (revolutions per
minute), by a motor supplying 1.5kW of power to it. If this power is considered the maximum for
the safe operation of the motor, then calculate the diameter of the lifting cable. Consider that the
cable is made out of steel having an ultimate strength of 450MPa, and a factor of safety of 3 is
deemed as adequate.
Hint: (The load on the cable is the force F acting on the outer edge of the drum. It can be found
from the formula:
F = (60*P)/(3.1416*D*N) F = kN P = power = kW, D = diameter = m, N = rpm
* = (multiplication sign). Review also lecture 3 section 1
answer _____________ mm.
1.9023
A beam of uniform cross section has a mass of 6.523 tons, and is 12m long. The beam is
supported at 3.6m from the left end and at 2.4m from the right end. It also carries loads:
150kN, 475kN, and 280kN at 1.2m, 7.2m, and 10.8m, respectively from the left end. Calculate
the reactions at the left and right supports. (Take the gravitational constant g=9.81N/kg or
m/sec².
R1 = ____________ kN. Reaction at the left support.
R2 = ____________ kN. Reaction at the right support.
382.3944
586.5963
The draft gauge on a forced draft boiler reads 228mm. of water. (Take the gravitational
constant g=9.81N/kg, or m/sec²
1. What is the gauge pressure in the boiler?
2. What is the absolute pressure in the boiler if the barometric pressure
in the locality is 101.0kPa?
A body's ability to resist change in shape and size under an applied load is known as:
a. Stiffness
b. Ductility
c. Toughness
d. Malleability
a
When classifying beams, the term simple beam refers to a beam:
a. That is supporting one concentrated load
b. That supports a uniform load
c. That is supported at two ends
d. Of the cantilever type
c
The term _________ is used as a measure of the quantity of matter.
a. Volume
b. Weight
c. Mass
d. Relative density
c
If we are given the values for the load and the area of an object,
we find the stress by dividing the load by the area.
T or F
t
The point at which a material passes its elastic limit and continues to deform
after the deforming force is removed is called it's _______ _______ .
yield point
A stress of 7520kPa is produced in a circular cross section piece of steel. Given that
Young's modulus for this steel is 201GPa, then calculate the strain produced in the steel.
0.000037
The draft gauge on a forced draft boiler reads 191mm. of water.
1. What is the gauge pressure in the boiler?
2. What is the absolute pressure in the boiler if the barometric pressure in the locality is
100.5kPa? (Take the gravitational constant g=9.81N/kg, or m/sec²
An "I" beam, supported at both ends is 18m long and carries a uniform distributed load
of 19kN/m. The beam supports a downward concentrated load of 265kN at 10.8m from
the left end. Calculate the shear force and bending moment at 7.2m and 12.6m from the
left end. Also give the sizes for left and right reactions.
Caution: (For parts c to f, give your answers as positive numbers only.)
a. Left reaction = ____________kN
b. Right reaction = ____________ kN
c. _________________ kN shear force at 7.2m from left
d. _________________ kN shear force at 12.6m from left
e. _________________ kN/m bending moment at 7.2m from left
f. _________________ kN/m bending moment at 12.6m from left
277
330
140.2
227.4
1501.9
1505.0
. If Young's Modulus and the stress that a body is subjected to
are known, which of the following can be calculated?
a. Area of the body
b. Bending moments
c. Amount of stretch produced
d. All of the above
c
A material's ability to resist a change in shape or size when a
load is applied is known as _______
stiffness
A _______ is a rigid member, in a structure or mechanism, which
is capable of carrying loads or forces.
beam
A cantilever beam is 8m long and carries a concentrated load of 125kN at its free end.
The beam is also uniformly loaded at11kN/m over its entire length. Calculate the shear
force and bending moment at the wall.
Caution: (Give your answers as positive numbers only)
a. __________ kN shear force
b. __________ kN/m bending moment
213.0
1352.0
A beam is 8.40m long. It carries two concentrated loads and an evenly distributed load. The
first load is 21kN and is located 3.360m from the left support. The second load is50kN and
located 6.720m from the left support. The last load is evenly distributed at 7.0kN/m over a span
of 5.040m starting on left support towards the right support. On the basis of the above calculate:
(Express your answers as positive numbers)
1) The reaction at the left support: ________________ kN.
2) The reaction at the right support: _______________ kN.
3) Shearing force and bending moment at 5.880m from the left support:
A mercury manometer at a condenser reads a difference of level between its two legs of
642mm of mercury as vacuum. If the atmospheric pressure at the locality is 101.2kPa,
Find the absolute pressure in kPa at that condenser. (Take the gravitational constant
g=9.81N/kg, or m/(sec. squared))
Ultimate strength of a material is expressed in units of:
a. Kilowatts
b. m²
c. Kilopascals
d. Joules
c
Factor of safety values are affected by:
a. Nature of the load
b. Government authorities
c. Corrosive service
d. All of the above
d
When conducting an ultimate tensile strength test, the cross-sectional area of the
specimen used for calculation is:
a. The area before the test is conducted
b. The area after the test is conducted
c. The area during the test
d. Always the area taken at 100°C
a
Reaction forces are those:
a. Those which support the beam
b. Clockwise moments
c. Internal forces in the beam
d. The sum of the clockwise moments
a
The relationship between the mass of a body and its volume is known as its:
a. Specific gravity
b. Relative density
c. Buoyancy
d. Density
d
Relative density of a substance is:
a. The mass of a substance compared to air.
b. The volume of a substance compared to water.
c. The mass of a substance compared to water.
d. None of the above
d
A certain belt is 110mm wide and 8mm thick, runs on a pulley 52cm in diameter. It is made out
of material having an ultimate strength of 14MPa. Considering a factor of safety of 5 calculate:
Hint: (For part 3 of this problem, review lecture four, section one)
1) The max. working stress ________ kPa.
2) The max. working tensile force it can carry when running __________ kN.
3) If it runs at 940rpm., the power it can transmit ___________ kW.
2800
2.4640
63.0624
A beam 20m in length is supported at two locations. The right support R2 is located 6.0m from
the right end of the beam. The left support R1 is 10.0m to the left of R2. The beam supports
loads of 150kN, 560kN and 135kN located respectively at the left end, 8.0m from the left end
and at the right end. Find the value of supports R1 and R2.
ans R1 = ____________ kN size of left support.
ans R2 = ____________ kN size of right support.
465.0
380.0
1. The amount of deformation compared to the original size of a body, in applied
mechanics, is referred to as:
a. Strain
b. Stress
c. Set
d. Variable
a
Pressure multiplied by area is:
a. Watts or kilowatts
b. Total force
c. Nm or J
d. All of the above
b
Steam under pressure in a boiler has:
a. An area
b. Energy of motion
c. Potential energy
d. Kinetic energy
c
The type of beam with the best strength to material mass ratio is the _______ ______.
i beam
A 13.6cm diameter piston rod is subjected to a maximum compressive load under working
conditions of one half MegaNewton. The tensile strength of the material is 201MPa.
Find the factor of safety
5.8397
A beam 11m long, simply supported, has a load of 12kN acting down upon it, 3.3 m from the
right hand support. Another load of 21kN is also acting on it 4.4m. from the left hand support.
If R1 is the reaction at the left support and R2 is the reaction at the right support, calculate R1
and R2.
a. R1 = ___________ kN
b. R2 = ___________ kN
16.2
16.8
A certain chimney is 29m high and is supported by a number of guy wires. Each guy wire
is anchored at 8.7m away from the base of the chimney, and at 23.2m high on the chimney,
in such a way that a right triangle is formed. The material the wires are made from has an
E = 200GPa, an ultimate strength of 900MPa, and each wire has a diameter of 4mm.
Considering a factor of safety of 6 calculate:
1) The extra length each wire stretches __________ mm
2) The working stress each wire carries __________ kPa
3) The tensile load each wire carries __________ kN
18.5832
150000
1.8850
An iron bar 30cm² in cross section, is subjected to a load of 2750N.
Calculate the stress in the iron bar
917kPa
A simple beam is:
a. Supported at one end only
b. Supported at both ends
c. Supported some distance from one end
d. Free of all supports
b
Reaction forces are those:
a. Those which support the beam
b. Clockwise moments
c. Internal forces in the beam
d. The sum of the clockwise moments
a
The formula, stress = load divided by the area, can be transposed
to read stress times load when you must solve to find the correct area.
T or F ?
f
E, or the modulus of elasticity, is also known as ______________.
young's module
When engineers built into a system an allowable working stress which is much
lower than the ultimate stress they are building in a _____ _____ _____.
factor of safety
A beam is 8.90m long. It carries two concentrated loads and an evenly distributed load.
The first load is 21kN. And is located 3.560m from the left support. The second load is
41kN. And located 7.120m from the left support. The last load is evenly distributed at
9.8kN/m over a span of 5.340m starting on left support towards the right support. On the
basis of the above calculate: (express your answer as even numbers)
1) The reaction at the left support: ________________ kN.
2) The reaction at the right support: _______________ kN.
3) Shearing force and bending moment at 6.230m.From the left support
Shearing Force: ________________ kN.
Bending Moment: ________________ kNm.
4) Repeat part (3), at 2.670m from the left support:
Shearing Force: ________________ kN.
Bending Moment: ________________ kNm
57.4324
56.8996
15.8996
115.4319
31.2664
118.4129
Calculate the pressure exerted by a column of liquid 8.02m high if the relative density of the
fluid is 0.73 (Take the gravitational constant g= 9.81 N/kg or m/sec²
57.4336kPa
A mercury manometer at a condenser reads a difference of level between its two legs of
596mm of mercury as vacuum. If the atmospheric pressure at the locality is 101.3kPa,
Find the absolute pressure in kPa at that condenser. (Take the gravitational constant
g= 9.81N/kg, or m/sec²
21.7841
The term "concentrated load" refers:
a. Only to loads supported by simple beams
b. Only to loads supported by cantilever beams
c. To loads which act at a single point on a beam
d. To beams in equilibrium
c
The relationship between the mass of a body and its volume is known as its:
a. Specific gravity
b. Relative density
c. Buoyancy
d. Density
d
The term _________ is used as a measure of the quantity of matter.
a. Volume
b. Weight
c. Mass
d. Relative density
c
Young's Modulus is a very important quantity for if it is known then the amount of stretching
produced by a given stress may be calculated.
T or F
t
The factor of safety for both new and used boilers is set by the ASME code.
T or F
f
To find the load, when the stress and the area are known, we must
multiply the stress by the area.
T or F
t
Another name for allowable working stress is _______. _______ _______
safe working stress
1. According to Hooke's Law the stress in an elastic body is directly proportional to the
strain if:
a. The yield point of the material is exceeded
b. The elastic limits of the material is not exceeded
c. The elastic limits of the material is exceeded
d. Young's Modulus remains constant
b
The term "concentrated load" refers:
a. Only to loads supported by simple beams
b. Only to loads supported by cantilever beams
c. To loads which act at a single point on a beam
d. To beams in equilibrium
c
Relative density of a substance is:
a. The mass of a substance compared to air.
b. The volume of a substance compared to water.
c. The mass of a substance compared to water.
d. None of the above
d
Steam under pressure in a boiler has:
a. An area
b. Energy of motion
c. Potential energy
d. Kinetic energy
c
The formula for both Hooke's Law and Young's Modulus can be written as
E = stress divided by strain.
T or F
t
A _______ beam has one fixed end and one free end.
cantilever
The diameter of the drum of a winch is 50cm. The drum is rotated at 140rpm (revolutions per
minute), by a motor supplying 2.2kW of power to it. If this power is considered the maximum
or the safe operation of the motor, then calculate the diameter of the lifting cable Consider that
the cable is made out of steel having an ultimate strength of 475MPa, and a factor of safety of
5 is deemed as adequate. Hint: (The load on the cable is the force F acting on the outer edge
of the drum. It can be found from the formula:
F = (60*P)/(3.1416*D*N) F = kN P = power = kW, D = diameter = m, N = rpm
* = (multiplication sign). Review also lecture 3 section 1
2.8363mm
A rod is 20 mm in diameter and has a tensile strength of 800MPa. If the rod supports a tensile
load of 50.27 kN, find the safety factor.