Equilibrium Physics Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

easy
A 40 N40 \text{ N} sign is held at rest by two vertical supports. One support pulls upward with 25 N25 \text{ N}. What upward force must the second support provide for equilibrium?

Solution

  1. 1
    For equilibrium, the total upward force must equal the 40 N40 \text{ N} downward weight.
  2. 2
    Let the second support provide force FF. Then 25+F=4025 + F = 40
  3. 3
    Solve: F=15 NF = 15 \text{ N}

Answer

15 N upward15 \text{ N upward}
An object in equilibrium has zero net force. If one support does not provide all of the upward force needed, the other support must provide the remainder.

About Equilibrium

A state in which all forces acting on an object balance so that the net force equals zero and there is no acceleration.

Learn more about Equilibrium →

More Equilibrium Examples

Example 1 easy

A [formula] lamp hangs from a single vertical cord. What is the tension in the cord?

Example 2 hard

A [formula] sign hangs from two cables, each making a [formula] angle with the horizontal. What is t

Example 3 medium

An object is in equilibrium under three forces: [formula] east, [formula] north. What is the magnitu

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