Power engineering 4th class chap 1-6 test practice
questions with complete solutions
Any action on a body, which tends to change its size, shape or its state of
motion is defined as: - ANSWER-force
__________ energy is the ability of a body to do work by virtue of its position. -
ANSWER-Potential
A body travels 163 m in 6 seconds. What is the velocity? - ANSWER-27.166
m/s
Which of the following is an example of a static body? - ANSWER-a rigid body
that is at rest.
A bar is pivoted on the right end and a force is applied downwards on the left
end. The rotation of the bar will be: - ANSWER-counter-clockwise
If a system of forces is in equilibrium, then which of the following statements
is true? - ANSWER-The total forces to the right = the total forces to the left.
A 5 m long bar is pivoted on the right end and a force of 10 N is applied
upwards on the left end. The moment of force is: - ANSWER-50 Nm clockwise
,An effort of 3 kN is required to move a mass of 2,000 kg in a certain simple
machine.If the mass is raised 1.5 m while the effort moves 12 m, find:
the velocity ratio (VR)
the actual mechanical advantage (MA)
and the efficiency (EFF) of the machine. - ANSWER-8, 6.54, 81.75
A simple wheel and axle has a wheel diameter of 3 m and an axle diameter of
25 cm. What effort is required to raise 850 kg if the efficiency is 87%? -
ANSWER-798.7
The ratio of the load to the effort is called: - ANSWER-actual mechanical
advantage
A simple wheel and axle has a wheel diameter of 2.3 m and an axle diameter of
92 mm. If an effort of 26 N is required to raise a mass of 16 kg, what is the
efficiency of the machine? - ANSWER-24.1
Find the magnitude and direction of 4 concurrent coplanar forces:
i) 10 N 32 degrees east of north
ii) 35 N 50 degrees east of north
iii) 25 N 72 degrees east of north
iv) 85 N 40 degrees east of south: - ANSWER-115 N 77 degrees east of south
A vector quantity has: - ANSWER-direction, magnitude and necessary units of
the quantity
,A scalar quantity has: - ANSWER-both magnitude and necessary units
Find the magnitude and direction of 3 coplanar forces of:
i) 40 N 45 degrees east of southii) 10 N westiii) 70 N 35 degrees east of north -
ANSWER-65 N 65 degrees east of north
A vehicle traveling at 100 km/h decelerate uniformly to 40 km/h in 15
seconds. How far will the vehicle travel in this time? - ANSWER-291
A vehicle that travels 150 km in 3 hours: - ANSWER-has an average speed of
50 km/h
The area under a velocity vs. time graph equals: - ANSWER-displacement
A body moves 180 degrees from Point A to Point B in a semicircular path. The
radius of the semicircle is 8 m. Calculate the displacement between Point A
and Point B: - ANSWER-16
In the SI system, the unit of force is called the Newton (N). One Newton is
equal to - ANSWER-1 kg m/s2
What is the kinetic energy possessed by a car, having a mass of 1500 kg and
travelling at a velocity of 50 km/h? - ANSWER-144.7
A body with a mass of 88 kg is moving at a velocity of 13.89 m/s. What is its
kinetic energy? - ANSWER-8489
, The ability to do work due to an object's motion is defined as: - ANSWER-
kinetic energy
Regarding the equation μ = FF/RN, which statement is correct: - ANSWER-The
values for FF and RN must be measured at right angles to each other.
Find the mass of the refrigerator, which is just started moving by a force of
6,350 N along a tile floor with a coefficient of friction of 0.30: - ANSWER-
2157.66
What are the units associated with "Coefficient of Friction": - ANSWER-there
are no units
If engineers require a material which would be able to be stretched and
reduced in cross section without breaking they would choose a material with
which of the following properties? - ANSWER-ductility
A unit of stress is: - ANSWER-kPa
A hole 3 cm in diameter is to be punched out of a steel plate 8 cm thick. The
shear stress of the material is 670 GPa. What load is required on the punch? -
ANSWER-5051.6
A compressive load of 219 kN is resisted by a rectangular strut which has one
side measuring 83 mm. If the stress in the strut is 164,909 kPa, what is the
length of the other side (or width) of the strut? - ANSWER-0.016
questions with complete solutions
Any action on a body, which tends to change its size, shape or its state of
motion is defined as: - ANSWER-force
__________ energy is the ability of a body to do work by virtue of its position. -
ANSWER-Potential
A body travels 163 m in 6 seconds. What is the velocity? - ANSWER-27.166
m/s
Which of the following is an example of a static body? - ANSWER-a rigid body
that is at rest.
A bar is pivoted on the right end and a force is applied downwards on the left
end. The rotation of the bar will be: - ANSWER-counter-clockwise
If a system of forces is in equilibrium, then which of the following statements
is true? - ANSWER-The total forces to the right = the total forces to the left.
A 5 m long bar is pivoted on the right end and a force of 10 N is applied
upwards on the left end. The moment of force is: - ANSWER-50 Nm clockwise
,An effort of 3 kN is required to move a mass of 2,000 kg in a certain simple
machine.If the mass is raised 1.5 m while the effort moves 12 m, find:
the velocity ratio (VR)
the actual mechanical advantage (MA)
and the efficiency (EFF) of the machine. - ANSWER-8, 6.54, 81.75
A simple wheel and axle has a wheel diameter of 3 m and an axle diameter of
25 cm. What effort is required to raise 850 kg if the efficiency is 87%? -
ANSWER-798.7
The ratio of the load to the effort is called: - ANSWER-actual mechanical
advantage
A simple wheel and axle has a wheel diameter of 2.3 m and an axle diameter of
92 mm. If an effort of 26 N is required to raise a mass of 16 kg, what is the
efficiency of the machine? - ANSWER-24.1
Find the magnitude and direction of 4 concurrent coplanar forces:
i) 10 N 32 degrees east of north
ii) 35 N 50 degrees east of north
iii) 25 N 72 degrees east of north
iv) 85 N 40 degrees east of south: - ANSWER-115 N 77 degrees east of south
A vector quantity has: - ANSWER-direction, magnitude and necessary units of
the quantity
,A scalar quantity has: - ANSWER-both magnitude and necessary units
Find the magnitude and direction of 3 coplanar forces of:
i) 40 N 45 degrees east of southii) 10 N westiii) 70 N 35 degrees east of north -
ANSWER-65 N 65 degrees east of north
A vehicle traveling at 100 km/h decelerate uniformly to 40 km/h in 15
seconds. How far will the vehicle travel in this time? - ANSWER-291
A vehicle that travels 150 km in 3 hours: - ANSWER-has an average speed of
50 km/h
The area under a velocity vs. time graph equals: - ANSWER-displacement
A body moves 180 degrees from Point A to Point B in a semicircular path. The
radius of the semicircle is 8 m. Calculate the displacement between Point A
and Point B: - ANSWER-16
In the SI system, the unit of force is called the Newton (N). One Newton is
equal to - ANSWER-1 kg m/s2
What is the kinetic energy possessed by a car, having a mass of 1500 kg and
travelling at a velocity of 50 km/h? - ANSWER-144.7
A body with a mass of 88 kg is moving at a velocity of 13.89 m/s. What is its
kinetic energy? - ANSWER-8489
, The ability to do work due to an object's motion is defined as: - ANSWER-
kinetic energy
Regarding the equation μ = FF/RN, which statement is correct: - ANSWER-The
values for FF and RN must be measured at right angles to each other.
Find the mass of the refrigerator, which is just started moving by a force of
6,350 N along a tile floor with a coefficient of friction of 0.30: - ANSWER-
2157.66
What are the units associated with "Coefficient of Friction": - ANSWER-there
are no units
If engineers require a material which would be able to be stretched and
reduced in cross section without breaking they would choose a material with
which of the following properties? - ANSWER-ductility
A unit of stress is: - ANSWER-kPa
A hole 3 cm in diameter is to be punched out of a steel plate 8 cm thick. The
shear stress of the material is 670 GPa. What load is required on the punch? -
ANSWER-5051.6
A compressive load of 219 kN is resisted by a rectangular strut which has one
side measuring 83 mm. If the stress in the strut is 164,909 kPa, what is the
length of the other side (or width) of the strut? - ANSWER-0.016
