4TH CLASS POWER ENGINEERING
PART A EXAM QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT RATED
A+
Space Diagram
✔✔ Answer:
A space diagram is used to visually represent a system of vectors and their
directions.
Co-planar Vectors
✔✔ Answer:
Co-planar vectors are vectors that lie within the same geometric plane.
Concurrent Vectors
✔✔ Answer:
Concurrent vectors are vectors whose lines of action intersect at a single point.
Resultant
✔✔ Answer:
A resultant is a single vector that represents the combined effect or sum of two or
more vectors.
Velocity (m/s) -ANSWER ✔✔Change in position / time
Acceleration (m/s^2) -ANSWER ✔✔Change in velocity (m/s) / time (s)
,Force (Newton) -ANSWER ✔✔mass (kg) x acceleration (m/s^2) , any action on a
body that tends to change its size, shape, or its state of rest or motion
Force of Gravity -ANSWER ✔✔mass (kg) x 9.81 m/s^2
Pressure (Pa) -ANSWER ✔✔Force (N) / area (m^2)
Work (J) -ANSWER ✔✔Force (N) x distance (m)
Power -ANSWER ✔✔Work done / time , Rate of doing work
Potential Energy (J) -ANSWER ✔✔mass x gravity x height , the ability of a body
to do work due by virtue of its position
Kinetic Energy (J) -ANSWER ✔✔1/2 x mass x velocity^2 , The ability of a body
to do work due to its motion
Energy (J) -ANSWER ✔✔The capacity of a body to do work
Tonne -ANSWER ✔✔1000 kilograms
Moment of Force (Nm) -ANSWER ✔✔Force (N) x Distance (m) , A force, acting
on a body at any distance from a point on that body, will tend to produce rotation
around that point
,Clockwise Moments -ANSWER ✔✔Equal to Counter-clockwise moments
Upward Forces -ANSWER ✔✔Equal to Downward forces
Actual Mechanical Advantage (Ma) -ANSWER ✔✔Load (N) / Effort (N)
Velocity Ratio (VR) -ANSWER ✔✔Distance moved by Effort / Distance moved
by Load
Efficiency -ANSWER ✔✔Output Work / Input Work
Output Work -ANSWER ✔✔Load x Distance moved by load
Input Work -ANSWER ✔✔Effort x Distance moved by effort , Equals Output
work + Wasted work
Ideal Mechanical Advantage (MA) -ANSWER ✔✔Equal to Velocity Ratio (VR)
Load x r -ANSWER ✔✔Equal to Effort x R
VR -ANSWER ✔✔Equal to R/r and D/d
Load /Effort -ANSWER ✔✔Equal to R/r
Scalar -ANSWER ✔✔A physical quantity that has magnitude but no direction
, Vector -ANSWER ✔✔A quantity that has magnitude and direction
Space Diagram -ANSWER ✔✔Illustrates a system of vectors
Co-planar Vectors -ANSWER ✔✔Vectors that are all in the same plane
Concurrent Vectors -ANSWER ✔✔Vectors whose lines of action meet at one
point
Resultant -ANSWER ✔✔A vector that represents the sum of two or more vectors
Absolute Pressure -ANSWER ✔✔Atmospheric pressure + gauge pressure
Static Friction -ANSWER ✔✔A friction force that acts on objects that are not
moving. Always greater than kinetic friction
Kinetic Friction -ANSWER ✔✔Friction that opposes motion once the motion has
already started. Not affected by speed of body Always greater than rolling friction.
Rolling Friction -ANSWER ✔✔The friction force that acts on rolling objects,
Always less than kinetic friction
Fluid Friction -ANSWER ✔✔Friction that occurs as an object moves through a
fluid
PART A EXAM QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT RATED
A+
Space Diagram
✔✔ Answer:
A space diagram is used to visually represent a system of vectors and their
directions.
Co-planar Vectors
✔✔ Answer:
Co-planar vectors are vectors that lie within the same geometric plane.
Concurrent Vectors
✔✔ Answer:
Concurrent vectors are vectors whose lines of action intersect at a single point.
Resultant
✔✔ Answer:
A resultant is a single vector that represents the combined effect or sum of two or
more vectors.
Velocity (m/s) -ANSWER ✔✔Change in position / time
Acceleration (m/s^2) -ANSWER ✔✔Change in velocity (m/s) / time (s)
,Force (Newton) -ANSWER ✔✔mass (kg) x acceleration (m/s^2) , any action on a
body that tends to change its size, shape, or its state of rest or motion
Force of Gravity -ANSWER ✔✔mass (kg) x 9.81 m/s^2
Pressure (Pa) -ANSWER ✔✔Force (N) / area (m^2)
Work (J) -ANSWER ✔✔Force (N) x distance (m)
Power -ANSWER ✔✔Work done / time , Rate of doing work
Potential Energy (J) -ANSWER ✔✔mass x gravity x height , the ability of a body
to do work due by virtue of its position
Kinetic Energy (J) -ANSWER ✔✔1/2 x mass x velocity^2 , The ability of a body
to do work due to its motion
Energy (J) -ANSWER ✔✔The capacity of a body to do work
Tonne -ANSWER ✔✔1000 kilograms
Moment of Force (Nm) -ANSWER ✔✔Force (N) x Distance (m) , A force, acting
on a body at any distance from a point on that body, will tend to produce rotation
around that point
,Clockwise Moments -ANSWER ✔✔Equal to Counter-clockwise moments
Upward Forces -ANSWER ✔✔Equal to Downward forces
Actual Mechanical Advantage (Ma) -ANSWER ✔✔Load (N) / Effort (N)
Velocity Ratio (VR) -ANSWER ✔✔Distance moved by Effort / Distance moved
by Load
Efficiency -ANSWER ✔✔Output Work / Input Work
Output Work -ANSWER ✔✔Load x Distance moved by load
Input Work -ANSWER ✔✔Effort x Distance moved by effort , Equals Output
work + Wasted work
Ideal Mechanical Advantage (MA) -ANSWER ✔✔Equal to Velocity Ratio (VR)
Load x r -ANSWER ✔✔Equal to Effort x R
VR -ANSWER ✔✔Equal to R/r and D/d
Load /Effort -ANSWER ✔✔Equal to R/r
Scalar -ANSWER ✔✔A physical quantity that has magnitude but no direction
, Vector -ANSWER ✔✔A quantity that has magnitude and direction
Space Diagram -ANSWER ✔✔Illustrates a system of vectors
Co-planar Vectors -ANSWER ✔✔Vectors that are all in the same plane
Concurrent Vectors -ANSWER ✔✔Vectors whose lines of action meet at one
point
Resultant -ANSWER ✔✔A vector that represents the sum of two or more vectors
Absolute Pressure -ANSWER ✔✔Atmospheric pressure + gauge pressure
Static Friction -ANSWER ✔✔A friction force that acts on objects that are not
moving. Always greater than kinetic friction
Kinetic Friction -ANSWER ✔✔Friction that opposes motion once the motion has
already started. Not affected by speed of body Always greater than rolling friction.
Rolling Friction -ANSWER ✔✔The friction force that acts on rolling objects,
Always less than kinetic friction
Fluid Friction -ANSWER ✔✔Friction that occurs as an object moves through a
fluid
