Question Detail

PHY 101 Mechanical Equilibrium and Rotational Dynamics Objective Question
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Question

For a body to be in absolute equilibrium (both translational and rotational), which two conditions must be satisfied?
Options
A The centre of mass has constant velocity, and the body has constant angular velocity.
B The sum of upward forces equals the sum of downward forces, and the sum of clockwise moments equals the sum of anticlockwise moments.
Correct Answer
C All forces intersect at a point, and the body is at rest.
D The net force is zero, and the centre of gravity is below the point of suspension.
Correct Answer

Option B is the correct answer.

Detailed Explanation

Absolute equilibrium requires no net force and no net torque. Translational equilibrium (no net force) is achieved when the vector sum of forces in all directions is zero, which for vertical forces means the algebraic sum of upward and downward forces equals zero. Rotational equilibrium (no net torque) is achieved when the algebraic sum of clockwise and anticlockwise moments about any point is zero.

Hint

Recall the two separate but necessary conditions for a body to be in complete mechanical equilibrium.

Question Info

Course: PHY 101
Topic: Mechanical Equilibrium and Rotational Dynamics
Type: Objective
Difficulty: Not specified
Question 568 of 1250
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