Does greater acceleration result in more work done?

In summary, the conversation discusses the relationship between work, force, mass, and distance. It is stated that work can be increased by increasing the force or distance, while also considering the effect of acceleration on work and kinetic energy. The equations W = Fs and F=ma are used to explain how doubling the acceleration will result in double the force, and therefore double the work done. The conversation also mentions the importance of considering other factors, such as friction, when calculating work and kinetic energy.
  • #1
Imperial Sky
4
0
Work W done by moving the object with force F for distance s is W = Fs.
When I move the same object the same distance but with twice the acceleration, does
the work done gets also doubled?
By F=ma, doubling the acceleration yields m*2*a = 2F -> 2Fs = 2W.

I've mostly read, that if I want to increase work, I must either increase the mass of the object or
the distance, which gets me confused, because acceleration is also in the equation.
 
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  • #2
I think your problem is saying that the same force can cause different acceleration.
As you say, F=ma, so to get double the acceleration you need twice the force.
Imperial Sky said:
I've mostly read, that if I want to increase work, I must either increase the mass of the object or
the distance, which gets me confused, because acceleration is also in the equation.
Well I wouldn't agree with that. Your original definition is the right one W=Fs so to increase work you must increase the force or the distance through which it moves.

Say you push a 5 kg mass with a force of 10 N over a distance of 3 m, then your work is 30 J.
If you treble the mass to 15 kg, but keep the force to 10 N, then over 3 m you still do 30 J of work.
The difference is that now the acceleration will be less and it will take you longer (time) to move through those 3 m.

You have to be clear about what changes you are making and ensure the changes you make are possible.
For example, you can't change acceleration but keep both force and mass the same, because F=ma. You can't change work if you keep both force and distance the same, because W=Fs.
 
  • #3
If I move a 1kg body with an acceleration of 1 m/s^2 (F = ma = 1N) for 1 meter, I do 1J work.
If I move the same 1kg body the same 1 meter distance, but with acceleration 2 m/s^2 (F=2N), does that mean that I did 2 times more work (2J) than before?
 
  • #4
Yes.
W = Fs = 2N x 1m = 2 J
 
  • #5
Imperial Sky said:
If I move a 1kg body with an acceleration of 1 m/s^2 (F = ma = 1N) for 1 meter, I do 1J work.
If I move the same 1kg body the same 1 meter distance, but with acceleration 2 m/s^2 (F=2N), does that mean that I did 2 times more work (2J) than before?
How much kinetic energy will the object gain in either scenario, if it starts from rest?
 
  • #6
In the first case, the work done is 1 J so it gains 1 J of KE if there is no friction etc.
In the second case, the work done is 2 J so it gains 2 J of KE if there is no friction etc.

You can check with your equations of motion:
1)## a= 1 m/sec^2 \ \ \ ⇒ v^2=2as = 2 \times 1 \times 1 = 2 m^2/sec^2 \ \ so \ \ KE = \frac {mv^2}{2} = \frac {1\times 2}{2} =1 J ##
2)## a= 2 m/sec^2 \ \ \ ⇒ v^2=2as = 2 \times 2 \times 1 = 4 m^2/sec^2 \ \ so \ \ KE = \frac {mv^2}{2} = \frac {1\times 4}{2} =2 J ##
 
  • #7
Imperial Sky said:
I've mostly read, that if I want to increase work, I must either increase the mass of the object or
the distance
That's assuming that the object starts at rest and ends at rest, as if for example we're lifting it off the floor and setting it on a table. The work done is ##mgh##, and ##g## is constant so to increase the work done we need either a heavier object or a higher table.

If the object is moving at a different speed when we're done, we also have to allow for the work done to change its kinetic energy. In your problem, the greater force over the same distance means a greater final speed and hence greater kinetic energy.
 
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Likes FactChecker

1. Does greater acceleration always result in more work done?

Yes, greater acceleration typically results in more work done. This is because work is directly proportional to force and displacement, and acceleration is a measure of how much force is needed to produce a certain change in velocity over a given time.

2. Can greater acceleration result in less work done?

In some cases, yes. If the acceleration is in the opposite direction of the applied force, the work done will be negative. This means that the object is losing energy instead of gaining it, resulting in less work done.

3. How does mass affect the relationship between acceleration and work done?

Mass does not directly affect the relationship between acceleration and work done. However, a heavier object may require more force to accelerate, resulting in more work done.

4. Is the relationship between acceleration and work done linear?

No, the relationship between acceleration and work done is not always linear. It depends on the object's mass, the applied force, and the direction of acceleration. In some cases, the relationship may be quadratic or even inverse.

5. Can work be done without acceleration?

Yes, work can be done without acceleration. As long as there is a force acting on an object and it moves in the direction of that force, work is being done. This is known as constant velocity or zero acceleration.

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