Equation for the tension in the string

In summary, the conversation discusses two objects, A and B, hanging down on either side of a smooth pulley and connected by an inextensible string. The masses of the objects are 3m and km respectively, and when released, object A accelerates at 2/5g. The value of k is asked for, and it is determined to be 1.29 by writing an equation for the tension in the string for both objects. However, it is mentioned that the value of k should be greater than 3, and it is suggested to assume that object A accelerates in the upward direction to get a value of k=7. The conversation ends with the acknowledgement that the original question was not read properly, and
  • #1
Gughanath
118
0
Two objects A and B hang down on either side of a smotth pulley, connected by an inextensible string. The masses of the objects are 3m and km respectivly. A accelerated at 2/5g when released. g=9.8N. What is the value of k.
I worked it out to be 1.29, by writing an equation for the tension in the string for both objects. But the the value of k is supposed to be greater than 3. :confused: Did I use the wrong method?
 
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  • #2
What direction does A accelerate? You assumed down, and got the correct answer for that assumption. If km > 3m, then A would accelerate up. Try making that assumption and solve for k.
 
  • #3
yes. This time round I get k=7? Is this right?
 
  • #4
Oh right. I didnt read the question properly. if k is bigger than 3, then obviously its the greater mass. Thanks for clearing my problem.
 

What is the equation for the tension in a string?

The equation for the tension in a string is T= F * L, where T is the tension in Newtons, F is the force applied to the string in Newtons, and L is the length of the string in meters.

How do you calculate the tension in a string?

To calculate the tension in a string, you can use the equation T= F * L, where T is the tension in Newtons, F is the force applied to the string in Newtons, and L is the length of the string in meters. You can also use a tension meter or force gauge to directly measure the tension in the string.

What factors affect the tension in a string?

The tension in a string can be affected by several factors including the force applied to the string, the length and thickness of the string, and the material and elasticity of the string. Changes in any of these factors can result in a change in the tension of the string.

What happens if the tension in a string is too high?

If the tension in a string is too high, it can cause the string to break or snap. Additionally, high tension in a string can also cause it to vibrate at a higher frequency and produce a higher-pitched sound.

How does the tension in a string affect the speed of a wave?

The tension in a string is directly proportional to the speed of a wave traveling through the string. This means that an increase in tension will result in an increase in wave speed, while a decrease in tension will result in a decrease in wave speed.

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