Finding Trajectory of x & y in Kinematics

  • Thread starter Kitanov
  • Start date
  • Tags
    Kinematics
In summary, the conversation is discussing finding a trajectory using the equations x = 4cos(2t) + 3sin(2t) and y = 3cos(2t) - 4sin(2t). The trajectory will repeat with a period of 2π and the velocity and acceleration can be determined using the equations and the Pythagorean theorem. The solution involves expressing cos(2t) and sin(2t), eliminating t using the equation cos^2 + sin^2 = 1, and combining the equations to find the trajectory.
  • #1
Kitanov
3
0
Thread moved from a technical forum, yada, yada... :-)
I need to find a trajectory

x = 4cos(2t) + 3sin(2t)
y = 3cos(2t) - 4sin(2t)
 
Physics news on Phys.org
  • #3
Kitanov said:
I need to find a trajectory
Will it repeat?
How often?
 
  • #4
Baluncore said:
Will it repeat?
How often?

I don't know what you think will happen again.
That's the whole task, there is no explanation of how the task is done. I can send you where that task is from, but you won't understand anything because it's in Serbian.

http://www.tfzr.uns.ac.rs/Content/files/0/Kinematika - I deo.pdf
Task 2
 
  • #5
The trajectory is a function of 2t.
Sine and cosine repeat evert 2π, so the trajectory will repeat. What period?
Plot values of x and y against t.
 
  • #6
Serbian is easy with google translate...
Page 6 of the .pdf
The question and a solution is presented on that page. I translate, but not all the equations.

Zadatak 2: Kretanje tačke određeno je jednačinama =
Task 2: The motion of a point is determined by equations

𝑥=4cos(2𝑡)+3sin(2𝑡)
𝑦=3cos(2𝑡)−4sin(2𝑡)
(𝑥, 𝑦 - in meters, 𝑡 - in seconds)

Odrediti trajektoriju (putanju), brzinu i ubrzanje tačke u trenutku kada je 𝑡=𝜋[𝑠]
= Determine the trajectory (trajectory), velocity and acceleration of a point at the moment when 𝑡 = 𝜋[𝑠]

Rešenje: = Solution:
Trajektorija (putanja) = Trajectory (path)
Dobijene jednačine kvadrirati i sabrati = Square and add the obtained equations
Brzina = Speed.
Ubrzanje = Acceleration.
 
  • #7
Baluncore said:
Serbian is easy with google translate...
Page 6 of the .pdf
The question and a solution is presented on that page. I translate, but not all the equations.

Zadatak 2: Kretanje tačke određeno je jednačinama =
Task 2: The motion of a point is determined by equations

𝑥=4cos(2𝑡)+3sin(2𝑡)
𝑦=3cos(2𝑡)−4sin(2𝑡)
(𝑥, 𝑦 - in meters, 𝑡 - in seconds)

Odrediti trajektoriju (putanju), brzinu i ubrzanje tačke u trenutku kada je 𝑡=𝜋[𝑠]
= Determine the trajectory (trajectory), velocity and acceleration of a point at the moment when 𝑡 = 𝜋[𝑠]

Rešenje: = Solution:
Trajektorija (putanja) = Trajectory (path)
Dobijene jednačine kvadrirati i sabrati = Square and add the obtained equations
Brzina = Speed.
Ubrzanje = Acceleration.

I speak Serbian. I understand what is written there, but it was not clear to me why it is done that way.
Now it is.
 
  • #8
Kitanov said:
I need to find a trajectory

x = 4cos(2t) + 3sin(2t)
y = 3cos(2t) - 4sin(2t)
express ##\cos 2t## and ##\sin 2t## and use ##\cos^2+\sin^2=1##
 
Last edited:

1. What is the definition of trajectory in kinematics?

Trajectory in kinematics refers to the path that an object takes through space as it moves. It can be described as a series of positions that the object occupies over time.

2. How is the trajectory of an object calculated in kinematics?

The trajectory of an object in kinematics is calculated using the equations of motion, which take into account the object's initial position, velocity, and acceleration. These equations can be solved to determine the object's position at any given time.

3. What factors can affect the trajectory of an object in kinematics?

The trajectory of an object in kinematics can be affected by various factors such as the object's initial velocity, acceleration, air resistance, and external forces acting on the object. These factors can cause the object's trajectory to change over time.

4. How does the trajectory of an object change when there is a change in acceleration?

When there is a change in acceleration, the trajectory of an object in kinematics can change in multiple ways. If the acceleration increases, the object's trajectory will become steeper and the object will move faster. On the other hand, if the acceleration decreases, the trajectory will become less steep and the object will slow down.

5. Can the trajectory of an object in kinematics be predicted accurately?

The trajectory of an object in kinematics can be predicted accurately as long as the initial conditions and factors affecting the object's motion are known. However, small variations in these factors can lead to significant changes in the trajectory, making it difficult to predict with 100% accuracy.

Similar threads

  • Introductory Physics Homework Help
Replies
13
Views
741
Replies
5
Views
938
  • Introductory Physics Homework Help
Replies
3
Views
868
  • Introductory Physics Homework Help
Replies
11
Views
961
  • Calculus and Beyond Homework Help
Replies
2
Views
395
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
25
Views
3K
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
709
  • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
Back
Top