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"The condition of equilibrium is when the sum of the forces acting on a body is the zero vector. Suppose a body has a force of 2 pounds acting on it to the right, 5 pounds acting on it upward, and 3 pounds acting on it 45° from the horizontal. What single force is needed to produce a state of equilibrium on the body?"

2 Answers

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Final answer:

To produce a state of equilibrium on the body, a force of 4.12 pounds to the left and 7.12 pounds downward is needed, which can also be expressed as a single resultant force calculated using the Pythagorean theorem and trigonometry.

Step-by-step explanation:

To achieve equilibrium for a body, the first condition that needs to be satisfied is that the net external force on the system must be zero, meaning net F = 0. In the given scenario, a body is subjected to three different forces: 2 pounds to the right, 5 pounds upward, and 3 pounds at a 45-degree angle from the horizontal. To find the single force that would balance these out, we must take vector components into account and sum them accordingly.

The force acting at 45 degrees can be split into horizontal and vertical components using trigonometry. The horizontal component (3 pounds × cos(45)) is approximately 2.12 pounds to the right, and the vertical component (3 pounds × sin(45)) is also approximately 2.12 pounds upward. Summing the horizontal forces: 2 pounds to the right + 2.12 pounds to the right = 4.12 pounds to the right. Summing the vertical forces: 5 pounds upward + 2.12 pounds upward = 7.12 pounds upward.

To create equilibrium, a single force with an equal magnitude but opposite direction is required. Therefore, a force of 4.12 pounds to the left and 7.12 pounds downward is needed. This can also be presented as a single resultant force by using the Pythagorean theorem: √(4.12² + 7.12²) pounds, which would be directed at an angle of tan⁻¹(7.12/4.12) from the horizontal.

User Fathi
by
4.1k points
1 vote

Answer:

The answer is
F= 2.881 pounds

Step-by-step explanation:

We will start this question by representing the force vectors in Cartesian coordinate system:

  • Force 1 acting on the right
    F_(1) = (2, 0)
  • Force 2 acting upward
    F_(2) = (0,5)
  • Force 3 acting at 45°
    F_(3) = (3cos(45),3sin(45))

Let the single force we need be represented by
F=(x,y)

Since, the body is in equilibrium the summation of all the forces acting on it should be zero:


F_(x) = 0 (Sum of all forces in
x direction is equal to zero)


x + 2 - 3cos(45) =0 (
x component of force 3 is negative because it is acting in opposite direction)


x = 0.1213


F_(y)=0 (Sum of all forces in
y direction is equal to zero)


y+5-3sin(45)=0 (
y component of force 3 is negative because it is acting in opposite direction)


y=-2.8786

So,


F=(0.1213,-2.8786)

Hence, to get the scalar quantity of a single force:


F=\sqrt[2]{(0.1213)^(2)+(-2.8786)^(2) }


F= 2.881 pounds

User Mark Tozzi
by
4.1k points