Can something keep on accelerating?

[sartisel]

Can something keep on accelerating?if d^2x/dt^2 can be regarded as acceleration, then what is d^3x/dt^3?

if not? why not?

constant acceleration = circular motion resolves it to be a infinite change of direction, however it does not answer the idea of magnitude.

 

[fss]

constant acceleration = circular motion resolves it to be a infinite change of direction, however it does not answer the idea of magnitude.

Doesn't matter. Acceleration is a change in a velocity vector. If either magnitude or direction changes, the vector changes.

 

[Ackbach]

Something can keep on accelerating as long as a force is applied to it. Eventually, though, you'll run into the issue of not being able to go faster than the speed of light.

$$\dfrac{d^{3}x}{dt^{3}}$$

is referred to as the jerk. You can see a reference http://en.wikipedia.org/wiki/Jerk_(physics)" .

 

[sartisel]

Something can keep on accelerating as long as a force is applied to it. Eventually, though, you'll run into the issue of not being able to go faster than the speed of light.

$$\dfrac{d^{3}x}{dt^{3}}$$

is referred to as the jerk. You can see a reference http://en.wikipedia.org/wiki/Jerk_(physics)" .

then how does terminal velocity come into play?

to be strictly speaking, something can keep on accelerating as long as an increasing force is applied right>?

 

[Drakkith]

then how does terminal velocity come into play?

to be strictly speaking, something can keep on accelerating as long as an increasing force is applied right>?

Terminal velocity is a result of an object moving through a medium which opposes its movement. Something like air or water. Depending on the density, size, and shape of the object, it will have a different terminal velocity than another object that is different.

Look up terminal velocity on Wikipedia.

 

[Ackbach]

Terminal velocity is a result of an object moving through a medium which opposes its movement. Something like air or water. Depending on the density, size, and shape of the object, it will have a different terminal velocity than another object that is different.

Look up terminal velocity on Wikipedia.

Typically, the resisting force is velocity-dependent, such that the force resists the motion more and more as the object increases speed. Eventually (as in the free-fall case), the resisting force equals the accelerating force, at which point the net force on the object is zero, and you get terminal velocity.

 

[epenguin]

then how does terminal velocity come into play?

to be strictly speaking, something can keep on accelerating as long as an increasing force is applied right>?

Wrong - something [STRIKE]can[/STRIKE] will keep accelerationg as long as [STRIKE]a constant[/STRIKE] any force is applied.

Terminal velocity arises when there is an opposite force so the total force on a body is zero - the one you are 'applying' is opposed by another velocity-dependent (increasing with) force, typically viscosity or friction, and at terminal velocity these have come into balance, i.e. are equal, i.e. net force is zero.

Nice example is sail propulsion in space. The force on the sails which is just the pressure of solar radiation is quite small, but the small constant acceleration will build up to a very high velocity eventually as there is so little matter in interplanetary space so little opposition from viscous type force. (I don't know what has been achieved in this way but it was receiving serious investments at one time.)

 

[Alan1000]

then how does terminal velocity come into play?

to be strictly speaking, something can keep on accelerating as long as an increasing force is applied right>?

As a non-physicist, I would assume that terminal velocity is the state achieved when a vector enters into a stable relationship with all of the forces which influence it, so far as they are constant. If any of the forces varies on a predictable basis, the notion of terminal velocity may become problematic but not beyond the bounds of rational description. If any forces vary on a random basis, then the notion of terminal velocity is truly prolematic, I would think?

Of course, if you were a Spitfire pilot in 1940, the answer is easy. How does terminal velocity (Vt) come into play? The wings break off.