# What is the tension in the string at the bottom of the swing?

• lbutscha
In summary, the conversation discusses the use of Newton's second law to determine the tension in a string when a pendulum with a length of 0.6 m and a bob with a mass of 1.0 kg has a speed of 1.9 m/s at the bottom of its swing. The formula v = sqrt(Forcetension/(m/L)) is suggested as a way to solve for the tension. The discussion also mentions that the acceleration is not zero at the bottom of the swing, but rather when the velocity is at its maximum.

#### lbutscha

A pendulum is 0.6 m long and the bob has a mass of 1.0 kg. At the bottom of its swing, the bob's speed is 1.9 m/s. What is the tension in the string at the bottom of the swing?

The attempt at a solution
I did Newtons second law F=ma. So I tried:

The sum of all forces=ma
T-W=ma
T=ma+w

I figured the acceleration would be zero when it is at the bottom of the swing. I have tried many different answers and can't seem to come up with the right one. Please help!

The acceleration is not zero at the bottom of the swing. Hint: What kind of motion does the bob undergo?

I am not exactly sure, but you might be able to use the equation v = sqrt(Forcetension/(m/L)).

I don't know how you derive this formula, but this is one of the formulas they give in my physics book (im actually doing the same thing right now in my class), so this should be what your looking for.

The acceleration would be zero only when the velocity is at it's max (I think).

Hope that helps.

I know it is nonuniform circular motion. But I still don't get it.

## 1. What is tension in a string?

Tension in a string is the force that is applied to the string in order to keep it taut or stretched. It is a pulling force that acts along the length of the string.

## 2. How is tension calculated in a string?

Tension can be calculated using the equation T = F * L, where T is tension, F is the force applied to the string, and L is the length of the string. Tension is measured in units of force, such as Newtons or pounds.

## 3. What factors affect the tension in a string?

The tension in a string can be affected by factors such as the weight of the object attached to the string, the length of the string, and the angle at which the string is pulled. Other factors such as the material and thickness of the string can also impact tension.

## 4. How does tension affect the motion of a swing?

Tension plays a crucial role in the motion of a swing. When a person sits on a swing, their weight creates tension in the string, which pulls the swing downwards. As the swing moves back and forth, the tension in the string changes, causing the swing to accelerate or decelerate.

## 5. Can tension in a string be greater than the weight of the object attached to it?

Yes, the tension in a string can be greater than the weight of the object attached to it. This is because tension is dependent on the force applied to the string, which can be greater than the weight of the object. However, if the tension becomes too great, the string may break.