Quake3World

Shown is a free body diagram of a mass with two vertical forces acting on it. From values given, can this object be moving, or is it at rest?

its resting

my cats breath smells like catfood

Let's see what the rest of the class thinks.

It is resting

It can be moving
The picture shows no pressures on the left or right hand side of the object

Only the forces shown are acting on it.

Don Carlos wrote:It can be moving
The picture shows no pressures on the left or right hand side of the object

Only 2 forces are mentioned and both are drawn.

In that case

The answer is C

If it's a "mass" and those two opposite forces are acting on it, won't it still be moving downward because it is a "mass"?

if those are the only two forces on it, then it's just not accelerating.

Could be moving at terminal velocity, with air resistance pushing up, and gravity pushing down at equilibrium.

[xeno]Julios wrote:if those are the only two forces on it, then it's just not accelerating.

Could be moving at terminal velocity, with air resistance pushing up, and gravity pushing down at equilibrium.

i thought of that too but as stated, only the 2 forces are shown can be taken into account?

Granted I'm an anthropologist/english major, so what the fuck do I know?

[xeno]Julios wrote:if those are the only two forces on it, then it's just not accelerating.

Could be moving at terminal velocity, with air resistance pushing up, and gravity pushing down at equilibrium.

DING! Jules wins.

Don Carlos wrote:

[xeno]Julios wrote:if those are the only two forces on it, then it's just not accelerating.

Could be moving at terminal velocity, with air resistance pushing up, and gravity pushing down at equilibrium.

i thought of that too but as stated, only the 2 forces are shown can be taken into account?

the upwards force would be the force of the air resistance, and the downward force would be gravity.

It could be moving sideways at a constant velocity too.

Nightshade wrote:

[xeno]Julios wrote:if those are the only two forces on it, then it's just not accelerating.

Could be moving at terminal velocity, with air resistance pushing up, and gravity pushing down at equilibrium.

DING! Jules wins.

Then the diagram is screwed up because air resistance doesnt pull a force it upwards, it resists it, hence the arrow for it should be on the opposite side of the box. Also since the box is a box, the air cavity associated with movement across a non-aerodynamic object would create a vacumn and as such a the air pressure on the top side would be lower resulting in a flux of the moving air around it. Because of the flux, the object would destabalise and horizontal forces would occur increasing the destabalisation of the object meaning that acceleration and deceleraton can and would occur.



So yeah, in lamons terms that diagram is shit, your question and answer is retarded and I am a genious and god like...

Nightshade wrote:

Shown is a free body diagram of a mass with two vertical forces acting on it. From values given, can this object be moving, or is it at rest?

It could be moving upwards on a platform that is going up or down at a stationary rate. It could also be stationary. Unless I am missing somethign here I am guessing, NS, that this is not a question you actually NEED people here to answer.

[FTF]Pyro wrote:

Nightshade wrote:

[xeno]Julios wrote:if those are the only two forces on it, then it's just not accelerating.

Could be moving at terminal velocity, with air resistance pushing up, and gravity pushing down at equilibrium.

DING! Jules wins.

Then the diagram is screwed up because air resistance doesnt pull a force it upwards, it resists it, hence the arrow for it should be on the opposite side of the box. Also since the box is a box, the air cavity associated with movement across a non-aerodynamic object would create a vacumn and as such a the air pressure on the top side would be lower resulting in a flux of the moving air around it. Because of the flux, the object would destabalise and horizontal forces would occur increasing the destabalisation of the object meaning that acceleration and deceleraton can and would occur.



So yeah, in lamons terms that diagram is shit, your question and answer is retarded and I am a genious and god like...

the diagram is about as common of a free body diagram as you'll find in basic physics texts, and that is probably all the question is asking....an object with balanced forces can be doing one of two things - staying at rest or moving with a constant velocity. And the arrow pointing up - the normal force - if we are calling that due to air resistance, than yea, it acts directly upwards, not as a pull, but as a push against the direction of movement.

and I should have read the rest of the thread.

[FTF]Pyro wrote:


So yeah, in lamons terms that diagram is shit, your question and answer is retarded and I am a genious and god like...

A genius with 1st grade spelling skills.

GRAMMAR FLAME.

SoM wrote:its resting

it's not resting, it's pining for the fjords.

Kills On Site wrote:Can it be moving if other forces are acting apon it, yes. Would it be moving if no other forces were acting apon it, I don't think so.

If you push and let go and object on a frictionless surface, it will start moving, and will keep on moving forever with a constant velocity given theres no resistance. No force will act on it after the push.

Depends on the frame of reference.