How Does a Pulley System Affect Scale Readings?

[orazon]

Homework Statement

Impact of pulling a rope connected to a mass through a pulley on the weight reading of that person

Relevant Equations

Pulleys, Springs

A kid is standing on a scale and holding a rope that goes through a pulley, on the other side the rope is connected to a spring and then to a 50N mass item.
Assume that the kid's weight is 700N
1. While in static mode - what will the scale show?
2. The kid is now pulling the rope to get the mass higher from the floor - what will be the impact on the scale measurement?

 

[BvU]

We need your best effort before we are allowed to help. Both for:

• What will the scale show ?
• What will be the impact ?

https://www.physicsforums.com/threads/homework-help-guidelines-for-students-and-helpers.686781/


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[orazon]

1. While in static mode, I believe that the scale will show 650 N as the Tension on the rope will counter some of the gravity force
2. While pulling the rope, the scale will show an even lower weight as the Tension in the rope will increase (even though the mass is moving) so the counter-force on gravity will be even higher.

 

[Hill]

2. While pulling the rope, the scale will show an even lower weight as the Tension in the rope will increase (even though the mass is moving) so the counter-force on gravity will be even higher.

What would be an effect of the spring?

 

[orazon]

Causing an increased tension on the rope?

 

[Hill]

Causing an increased tension on the rope?

Does it make any difference that the mass is on the spring rather than attached to the rope directly?

 

[orazon]

The tension will still be the same, right?

 

[Hill]

The tension will still be the same, right?

With the spring, the response will be dynamic.

 

[PeroK]

The tension will still be the same, right?

It would be good to try this out! Would the spring's response depend on how the rope was pulled? Could this get complicated?