What is the tension felt when a rock is dropped off a cliff connected to a rope?

In summary, the conversation discusses the weight and tension of a rock being dropped off a cliff while connected to a rope. The individual wonders how heavy the rock would "feel" when the slack runs out and if it has to do with momentum. The concept of force and the role of acceleration are also mentioned. In conclusion, the individual suggests considering the force exerted on the hand and calculating the mass based on the acceleration of 9.81.
  • #1
amcavoy
665
0
This isn't a HW question, just a thought. If I held a rock in my hand and connected it to a rope which I held in my other hand, then dropped it off of a cliff, how heavy would it "feel" when the slack ran out?

I know that the force is the same the entire way down, but when the slack ran out there would be a tension force going upwards towards me. However, it is obvious that it has to do with more than the acceleration, which would assume the tension of the rock just sitting there, not having been dropped.

Is it something to do with momentum? I know p=mv, so If I replaced v with at, I come up with p=m(at). How can I find the tension knowing the momentum?

Thanks for your help.

Alex
 
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  • #2
apmcavoy said:
This isn't a HW question, just a thought. If I held a rock in my hand and connected it to a rope which I held in my other hand, then dropped it off of a cliff, how heavy would it "feel" when the slack ran out?
I know that the force is the same the entire way down, but when the slack ran out there would be a tension force going upwards towards me. However, it is obvious that it has to do with more than the acceleration, which would assume the tension of the rock just sitting there, not having been dropped.
Is it something to do with momentum? I know p=mv, so If I replaced v with at, I come up with p=m(at). How can I find the tension knowing the momentum?
Thanks for your help.
Alex

I think I know what you're getting at, in which case I'd suggest also seeing that p = (ma)t , now, the question of what would it 'feel' like would kind of be a question of what exactly you'd consider as the 'feel'. Personally, I'd say that what it feels like would be the force it exerts on the hand. .. and then to put it into a perspective for others I'd take it as a weight .. and thus I could do mass based on 9.81 for the a. (which, if its free falling really tells a lot)
 
  • #3
By feel I mean the tension at the moment the rope runs out of slack and the rock stops its freefall (stopped by the rope).

Thanks,

Alex
 

1. What is force?

Force is a physical quantity that can cause an object to accelerate or deform. It is usually represented by the symbol F and is measured in units of Newtons (N).

2. How is force related to tension?

Tension is a type of force that is transmitted through a rope, string, or cable when it is pulled tight. In order for an object to experience tension, there must be an external force acting on it, such as gravity or a person pulling on the rope. Tension is also known as a "pulling force."

3. What factors affect tension?

The factors that affect tension include the magnitude of the external force, the angle at which the force is applied, and the properties of the material the rope or cable is made of. For example, a thicker and stronger rope will be able to withstand a higher tension force than a thinner and weaker one.

4. How is tension calculated?

Tension can be calculated using the formula T = F * sinθ, where T is tension, F is the external force, and θ is the angle at which the force is applied. This formula applies to a single rope or cable. If there are multiple ropes or cables involved, the total tension can be calculated by adding up the individual tensions.

5. What are some real-life examples of tension?

Some real-life examples of tension include a person pulling a wagon by a rope, a tightrope walker balancing on a rope, a suspension bridge with cables supporting it, and a bungee jumper attached to a bungee cord. Tension is also present in everyday objects such as rubber bands, springs, and guitar strings.

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