What is the solution to the Kinematics of Particles Homework?

In summary, the conversation discusses the calculation of tension before and after a string is cut in a physics problem, using the equation ∑Fy=0 before the string is cut. The approach is to sum the two forces in the y direction before the string is cut, which gives T in terms of mg, and then to sum the forces after the string is cut, which gives T minus mgcos40. There is some confusion over the use of cos40 in the calculation and the direction of the y-axis in the second diagram. The final conclusion is that taking the y-axis to be at an angle of 40 degrees results in the correct answer.
  • #1
Auburn2017
59
1

Homework Statement


Refer to figure please.

Homework Equations


∑Fy=0 before string is cut

The Attempt at a Solution


I tried summing the two forces in the y direction before the strings were cut which would be the two tensions at a sin40° and minus the weight of the ball(mg). That gave me T in terms of mg. Then I summed the forces when the string was cut and got T minus mgcos40. Then I thought that would be my ratio but my answer didnt match that of the solution. Help Please!
 

Attachments

  • delete me 6.jpg
    delete me 6.jpg
    28.8 KB · Views: 441
Physics news on Phys.org
  • #2
Your approach seems good. Are you sure that you should be using cos40o in the calculation after the string is cut? You left out the details of your calculations and you did not state what you actually got for the tension before and after one of the strings is cut.
 
  • Like
Likes Auburn2017
  • #3
TSny said:
Your approach seems good. Are you sure that you should be using cos40o in the calculation after the string is cut? You left out the details of your calculations and you did not state what you actually got for the tension before and after one of the strings is cut.
This is what I ended up doing. Does my work look right or did I just happen to get it right? Oh and there should be a mg on the end of my T=0.643 equation. I don't really know why I used mgsinΘ, I just know it gets you the right answer. An explanation on that would be greatly appreciated.
 

Attachments

  • answer.jpg
    answer.jpg
    25.9 KB · Views: 400
  • #4
In your first diagram your analysis looks good. Here you are taking the y-axis to be vertically upward.

In your second diagram (one string), what direction are you taking for the y-axis? Also, you should show the gravitational force in this diagram.
 
  • #5
TSny said:
In your first diagram your analysis looks good. Here you are taking the y-axis to be vertically upward.

In your second diagram (one string), what direction are you taking for the y-axis? Also, you should show the gravitational force in this diagram.
Oh that is what it is. If you take the y-axis to be at an angle of 40 degrees then the y component of the weight becomes mg sin40. Makes sense now.
 
  • #6
OK. Good work.
 
  • Like
Likes Auburn2017

FAQ: What is the solution to the Kinematics of Particles Homework?

What is Kinematics of Particles?

The Kinematics of Particles is a branch of physics that studies the motion of particles without considering the forces that cause the motion. It involves analyzing the position, velocity, and acceleration of a particle as it moves through space and time.

What is the difference between displacement and distance in Kinematics of Particles?

Displacement refers to the change in position of a particle in a specific direction, while distance is the total length of the path traveled by the particle. Displacement is a vector quantity, while distance is a scalar quantity.

How is velocity calculated in Kinematics of Particles?

Velocity is calculated by dividing the change in position (displacement) by the change in time. It is a vector quantity and includes both magnitude (speed) and direction.

What is the difference between speed and acceleration in Kinematics of Particles?

Speed refers to the rate at which an object is moving, while acceleration is the rate at which the speed is changing. Acceleration can also be described as the change in velocity over time.

How is Kinematics of Particles used in real-life applications?

Kinematics of Particles has many real-life applications, including in the design and analysis of vehicles and machines, sports, and other forms of motion. It is also used in navigation and GPS systems, as well as in understanding the motion of celestial bodies in space.

Similar threads

"Tension: T1 vs T2 - What is Correct?
Replies
1
Views
2K
Resolving forces: Mass on a string
Replies
4
Views
3K
Calculating Tension and Net Force in Suspended Cable System
Replies
3
Views
2K
What's the acceleration of the blocks and the tension?
Replies
10
Views
2K
Kinematics: baseball toss with an angle provided
Replies
3
Views
4K
Average tension force acting on a simple pendulum
Replies
32
Views
8K
Force on a pin from a pendulum and a string
Replies
4
Views
3K
What Is the Minimal Tension Angle for a Mass Pulled Horizontally?
Replies
4
Views
4K
Tension force and acceleration Problem
Replies
1
Views
2K
Quick Question about Torque and Tension
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top