Work Done by Tension in Cable: More Than Gravity?

In summary, "work done by tension" in a cable refers to the energy required to lift or move an object using the cable, taking into account the force applied by tension and the distance traveled. Tension in a cable differs from gravity as it is a pulling force exerted by the cable, while gravity pulls objects towards the center of the Earth. It is possible for tension in a cable to be greater than gravity, which occurs when the weight of the object is less than the tension force. The angle of the cable affects the work done by tension by increasing the amount of work required and reducing the effective force lifting the object. The tension in a cable is influenced by factors such as the weight of the object, angle of the cable,
  • #1
rootX
478
4
This questions asks what is the work done by the tension in the cable. And, the book answered that it is equal to the work done by the gravity.
But shouldn't it be more than the work done by the gravity? (because there is also a horizontal displacement)
see the attached image
attachment.php?attachmentid=9780&stc=1&d=1176673900.jpg
 

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  • #2
I can't see your attachment yet, what is the direction of the force? So what is [itex]\vec{F} \cdot \vec{d}[/itex] ?

AM
 
  • #3


The work done by the tension in the cable is a result of both the vertical and horizontal components of the force acting on the cable. While the work done by gravity is only in the vertical direction, the tension in the cable also contributes to the horizontal displacement of the object. Therefore, the work done by tension will be greater than the work done by gravity alone. This can be seen by considering the total work done on the object, which is equal to the change in its kinetic energy. If the object is moving both vertically and horizontally, the total work done will be the sum of the work done by both gravity and tension. So while the work done by gravity may be equal to the work done by tension in the vertical direction, the total work done by tension will be greater due to its contribution to the horizontal displacement of the object. It is important to consider all components of the forces acting on an object in order to accurately calculate the work done.
 

FAQ: Work Done by Tension in Cable: More Than Gravity?

What is meant by "work done by tension" in a cable?

The "work done by tension" in a cable refers to the amount of energy required to lift or move an object using a cable. It takes into account the force applied by the tension in the cable and the distance over which the object is moved.

How is tension in a cable different from gravity?

Tension in a cable is a pulling force that is exerted by the cable itself, whereas gravity is a force that pulls objects towards the center of the Earth. The direction of tension in a cable is always parallel to the length of the cable, while the direction of gravity is always towards the center of the Earth.

Can tension in a cable be greater than gravity?

Yes, tension in a cable can be greater than gravity. This occurs when the weight of the object being lifted or moved is less than the force applied by the tension in the cable. In this case, the cable will be able to lift the object, even if gravity is pulling it downwards.

How does the angle of the cable affect the work done by tension?

The angle of the cable affects the amount of work done by tension in two ways. First, the greater the angle between the cable and the ground, the more work is required to lift the object. Second, if the cable is at an angle, some of the tension force is pulling horizontally instead of vertically, which reduces the effective force lifting the object and thus requires more work to lift it.

What factors affect the tension in a cable?

The tension in a cable is affected by several factors, including the weight of the object being lifted, the angle of the cable, the length and thickness of the cable, and the strength and condition of the cable. Additionally, external forces such as wind or friction can also affect the tension in a cable.

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