What defines a particle in mechanics?
Its mass is considered concentrated at a point due to negligible size.
What is a rigid body in mechanics?
A combination of particles with unchanged shape and size.
How is a rigid body sometimes modeled?
As a particle with weight acting at its center of mass.
What does statics study in mechanics?
How an object remains in equilibrium.
What does dynamics study in mechanics?
Why and how an object follows a motion.
What does mass measure in a body?
The inertia of the body.
What kind of quantity is force in physics?
A vector quantity.
Which SI base units are used in mechanics?
Meters for length, seconds for time, and kilograms for mass.
What is the SI unit of force and its relation to mass and acceleration?
The newton, defined as .
What acceleration does one newton produce on a one-kilogram mass?
One meter per second squared.
What does Newton's first law state about a particle's motion?
It remains at rest or moves with constant velocity if no unbalanced force acts.
What does Newton's second law say about force and acceleration?
Acceleration magnitude is directly proportional to the resultant force on mass m.
How are the action and reaction forces between two particles related?
They are equal, opposite, and collinear.
What three branches does engineering mechanics use to study force effects?
Rigid-body mechanics, deformable-body mechanics, and fluid mechanics.
What does solid mechanics study in engineering mechanics?
How an object deforms.
What defines a scalar quantity in physics?
It has only magnitude without direction.
What two properties define a vector quantity?
Magnitude and direction.
How is a two-dimensional vector represented in Cartesian coordinates?
By components along x and y axes with unit vectors i and j.
What is a unit vector in a coordinate system?
A dimensionless vector with magnitude one expressing direction.
What does a position vector connect in a Cartesian system?
Two given positions.
What does the magnitude of a position vector represent?
The distance between the two points.
What does the dot product determine about a vector relative to a line?
Its component parallel or perpendicular to the line.
What type of quantity does the dot product produce?
A scalar.
What is the formula for the moment or torque of a force about a point?
What does the cross product of two vectors produce?
A vector perpendicular to their plane.
How is the magnitude of the cross product calculated?
By multiplying their magnitudes and the sine of the angle between them.
What rule determines the direction of a cross product and a 3D moment?
The right-hand rule.
What does the dot product use and what type of result does it give?
It uses cosine and gives a scalar.
What does the cross product use and what type of result does it give?
It uses sine and gives a vector.
For what physical concepts is the cross product used?
Perpendicular area and rotational tendency.
What is a concentrated force?
A single point load or load over a small area.
Which forces are considered fundamental in physics?
Gravitational, weak nuclear, electromagnetic, and strong nuclear forces.
Name three SI prefixes for large quantities and their powers of ten.
Giga (), mega (), kilo ().
Name three SI prefixes for small quantities and their powers of ten.
Milli (), micro (), nano ().
What is the gravitational force on an object near Earth called?
Its weight.
On what factors does an object's weight near Earth depend?
The masses of the object and Earth and the distance between their centers.
Which motions are included in rigid-body mechanics?
Translation, rotation, and general motion.
How are perpendicular vectors added to find the resultant?
By forming a right triangle and using Pythagoras’ theorem.
What condition must vectors meet to be added or subtracted?
They must be of the same type.
Which vectors represent coordinate directions in Cartesian systems?
The unit vectors i, j, and k.
How does vector -A relate to vector A in magnitude and direction?
It has the same magnitude but opposite direction.
How is a force along a line represented as a Cartesian vector?
By multiplying its magnitude by the unit vector along that line.
How does a smaller moment arm affect the force needed for the same moment?
It requires more force.
Answer 22 questions on Engineering Mechanics Fundamentals.
1. When can a body be modeled as a particle in mechanics?
2. What characteristic defines a rigid body in mechanics?
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