Is Your Calculation of Simple Harmonic Motion Accurate?

AI Thread Summary
The discussion focuses on the accuracy of calculations related to simple harmonic motion, particularly in problems involving acceleration and velocity. The original poster is confident in their first equation but uncertain about their results for the second and third problems, despite confirming acceleration with a teacher. Participants point out errors in unit conversions and suggest using calculus to derive velocity and acceleration from position equations. Clarification is sought on the source of certain values and the differentiation process necessary for accurate calculations. Understanding these concepts is crucial for resolving the issues presented in the problems.
Krokodrile
Messages
45
Reaction score
3
Homework Statement
Determinate amplitude, velocity, aceleration, and ecuation of the principal ecuations (more information in the down image)
Relevant Equations
1/T w/2pi
Captura de Pantalla 2021-04-30 a la(s) 1.58.02.png

The first ecuation values i am 99% that is correct. But, in the second and three problem i don't know if my results are ok. The problem number 2 i comprobate with the teacher that te aceleration its correct, so, with this i calculate the velocity.

I use like example the second problem for try resolve the 3rd problem, but causes me much problems.
Any help, please?
 

Attachments

  • Captura de Pantalla 2021-04-30 a la(s) 1.45.29.png
    Captura de Pantalla 2021-04-30 a la(s) 1.45.29.png
    29.7 KB · Views: 225
Physics news on Phys.org
Krokodrile said:
The first ecuation values i am 99% that is correct.
Except D.

Krokodrile said:
The problem number 2 i comprobate with the teacher that te aceleration its correct, so, with this i calculate the velocity.
In a), why the +50?
In B), how did you calculate the velocity?
In C), despite your teacher's confirmation, I get a much smaller value.

Krokodrile said:
I use like example the second problem for try resolve the 3rd problem, but causes me much problems.
I don't understand how you got any of those. Please explain your reasoning.
 
haruspex said:
Except D.In a), why the +50?
In B), how did you calculate the velocity?
In C), despite your teacher's confirmation, I get a much smaller value.I don't understand how you got any of those. Please explain your reasoning.
a) Thats my mistake, i put hz in angle.
b) The velocity: the teacher just give us the ecuation 0.1cos (314.16t+angle), i the formula v= 2pi/w: 2pi/0.02
c) Maybe I am wrong with the value copy, but i sure that say us 914.16 with m/s units.For the 3rd problem I'm on my own with a single "class", i put the values in the ecuation of the best way i can.
For the circular frecuency i used the formula w/2pi.
For the aceleration i try to work the aceleration value with pi
 
b) have you had calculus? taking the derivative of the position x(t) will give you an equation for the velocity. The max amplitude should be apparent from that

c) m/s corresponds to a velocity, not acceleration. similar to (b) above, taking the derivative of v(t) will give you acceleration
 
onatirec said:
b) have you had calculus? taking the derivative of the position x(t) will give you an equation for the velocity. The max amplitude should be apparent from that

c) m/s corresponds to a velocity, not acceleration. similar to (b) above, taking the derivative of v(t) will give you acceleration
Captura de Pantalla 2021-04-30 a la(s) 16.17.55.png
I tried make it better
 

Attachments

  • Captura de Pantalla 2021-04-30 a la(s) 16.16.34.png
    Captura de Pantalla 2021-04-30 a la(s) 16.16.34.png
    16.1 KB · Views: 129
Krokodrile said:
b) The velocity: the teacher just give us the ecuation 0.1cos (314.16t+angle), i the formula v= 2pi/w: 2pi/0.02
##100\pi## r/s is the angular velocity, which is constant. The question is asking for the maximum linear velocity, i.e. the maximum rate of change of x.
See @onatirec's advice above.
Krokodrile said:
c) Maybe I am wrong with the value copy, but i sure that say us 914.16 with m/s units.
The units are wrong for an acceleration, and if we correct the units to ##m/s^2## the number is wildly wrong. I want to know how you calculated it.
It sounds like someone gave you the answer but you wrote it down wrongly, and don't know how to find it for yourself. Is that right?
Krokodrile said:
For the circular frecuency i used the formula w/2pi.
But where does the value of 0.02 r/s for w come from?
Krokodrile said:
For the aceleration i try to work the aceleration value with pi

Here's how this stuff works:
##x(t)=A\sin(\omega t+\phi)##
Differentiate to find the velocity:
##v(t)=\frac{dx}{dt}=A\omega\cos(\omega t+\phi)##
Differentiate again to find the acceleration :
##a(t)=\frac{dv}{dt}=-A\omega^2\sin(\omega t+\phi)##

Do you understand those differentiation steps?
 
Thread 'Minimum mass of a block'
Here we know that if block B is going to move up or just be at the verge of moving up ##Mg \sin \theta ## will act downwards and maximum static friction will act downwards ## \mu Mg \cos \theta ## Now what im confused by is how will we know " how quickly" block B reaches its maximum static friction value without any numbers, the suggested solution says that when block A is at its maximum extension, then block B will start to move up but with a certain set of values couldn't block A reach...
TL;DR Summary: Find Electric field due to charges between 2 parallel infinite planes using Gauss law at any point Here's the diagram. We have a uniform p (rho) density of charges between 2 infinite planes in the cartesian coordinates system. I used a cube of thickness a that spans from z=-a/2 to z=a/2 as a Gaussian surface, each side of the cube has area A. I know that the field depends only on z since there is translational invariance in x and y directions because the planes are...
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'
Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is(Figure 2): F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
Back
Top