# Simple Harmonic Motion Query

Watch
Announcements

Page 1 of 1

Go to first unread

Skip to page:

Hi, in a simple harmonic motion, is the acceleration in the same direction as the displacement and velocity? is the force in the same direction as the velocity? is the velocity in the same direction as the displacement? Thanks

0

reply

Report

#2

Hiya - what subject is this for? I'll move it into the specific subject forum and you'll be more likely to get a good answer there

0

reply

Report

#3

(Original post by

Hi, in a simple harmonic motion, is the acceleration in the same direction as the displacement and velocity? is the force in the same direction as the velocity? is the velocity in the same direction as the displacement? Thanks

**Charlie1523**)Hi, in a simple harmonic motion, is the acceleration in the same direction as the displacement and velocity? is the force in the same direction as the velocity? is the velocity in the same direction as the displacement? Thanks

Force is proportional to acceleration so the above is true for force also.

Velocity is in the same direction as displacement.

Posted from TSR Mobile

1

reply

Report

#4

(Original post by

Hiya - what subject is this for? I'll move it into the specific subject forum and you'll be more likely to get a good answer there

**Fox Corner**)Hiya - what subject is this for? I'll move it into the specific subject forum and you'll be more likely to get a good answer there

Posted from TSR Mobile

0

reply

Report

#5

**Charlie1523**)

Hi, in a simple harmonic motion, is the acceleration in the same direction as the displacement and velocity? is the force in the same direction as the velocity? is the velocity in the same direction as the displacement? Thanks

In the case where the displacement and acceleration are at it's maximum due to the string applying it's maximum force. The force (acceleration) on the string would then be in the

**opposite direction**to the displacement.

Hence why the equation is

**Fox Corner**)

Hiya - what subject is this for? I'll move it into the specific subject forum and you'll be more likely to get a good answer there

1

reply

Report

#6

It's best to remember it using its derivations, i.e. if:

... comparing the functions, acceleration and force are in the opposite direction to the displacement, and the velocity is in antiphase with the others.

**x = asin(****ωt)****v = dx/dt =****ωacos(****ωt)****a = F/m = dv/dt = -****ω**^{2}**asin(****ωt)**... comparing the functions, acceleration and force are in the opposite direction to the displacement, and the velocity is in antiphase with the others.

1

reply

Report

#7

**Charlie1523**)

Hi, in a simple harmonic motion, is the acceleration in the same direction as the displacement and velocity? is the force in the same direction as the velocity? is the velocity in the same direction as the displacement? Thanks

The restoring force will act upwards, towards the equilibrium position, and so the acceleration must act in the same direction (F=ma). The mass's velocity must also be upwards.

But what happens once the mass has gone past the equilibrium position? The mass is still travelling upwards but the displacement is now negative (because it's the other side of the equilibrium position), and now the force and acceleration are now acting downwards. The mass's velocity decreases until it stops -at this point it has reached maximum negative displacement. It then starts accelerating downwards, so the velocity also acts downwards.

So, the force and acceleration always act in the opposite direction to displacement, as this is characteristic of simple harmonic motion. However, the relative directions of the velocity and the acceleration and displacement vary.

See the posts above for a mathematical explanation.

1

reply

Report

#8

(Original post by

Velocity is in the same direction as displacement.

Posted from TSR Mobile

**pineneedles**)Velocity is in the same direction as displacement.

Posted from TSR Mobile

0

reply

X

Page 1 of 1

Go to first unread

Skip to page:

### Quick Reply

Back

to top

to top