Acceleration proportional to velocity

In summary, a particle is accelerated from rest with acceleration proportional to its velocity. After traveling 10 meters, the speed is 35 m/s. To find the speed after the particle has traveled 20 meters, we use the equation a = v dv/dx = kv and integrate both sides to get v = kx. Dividing by v is allowed in this case as long as v is not equal to zero.
  • #1
s0laris
5
0

Homework Statement


A particle is accelerated from rest with acc. proportional to velocity. After traveling 10 meters the speed is 35 m/s, find the speed after the particle traveled 20 meters. (Changed the numbers a bit from the original so the answer ppbly will not be clean.)

Homework Equations



a=v dv/dx possibly

The Attempt at a Solution


Sat on this one for a long, long time

Tanks in advance
 
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  • #2
"Tanks"?

No, a is not "v dv/dx". Rather a= dv/dx which, here, is proportional to v:
a= dv/dx= kv for some number k.

From that dv/v= kdx. Now integrate both sides.
 
  • #3
a = dv/dt, I think you mean?
 
  • #4
Yea, watch out for those advancing tanks; hah, no I meant to say thanks.
Anyway, I do believe that a= v dv/dx ; dv/dt = (dv/dx)(dx/dt) = v (dv/dx). Does this seem reasonable:
a=kv=v dv/dx
k=dv/dx
k dx = dv
intg.
v=kx
? or is dividing by v not allowed => loss of roots or something?
 
  • #5
I do believe you're right, a = v dv/dx. (In one dimension of course) And I don't see anything wrong with your work.

Can you think of a reason why dividing by v would not be allowed? (hint: what number(s) are you not allowed to divide by?)
 

Related to Acceleration proportional to velocity

Question 1: What is acceleration proportional to velocity?

Acceleration proportional to velocity is a scientific concept that describes the relationship between acceleration and velocity. It states that when an object accelerates, its velocity changes at a rate that is directly proportional to the amount of acceleration.

Question 2: How is acceleration proportional to velocity calculated?

The mathematical formula for acceleration proportional to velocity is a = kv, where a is the acceleration, k is a constant, and v is the velocity. This means that as the velocity increases, the acceleration also increases, and vice versa.

Question 3: What are some real-life examples of acceleration proportional to velocity?

One common example of acceleration proportional to velocity is a car accelerating on a straight road. As the car's speed increases, its acceleration also increases. Another example is a roller coaster, where the acceleration is directly proportional to the velocity as the ride goes up and down.

Question 4: How does acceleration proportional to velocity relate to Newton's Second Law of Motion?

Acceleration proportional to velocity is a direct result of Newton's Second Law of Motion, which states that the force applied to an object is equal to its mass multiplied by its acceleration. In other words, the greater the force applied to an object, the greater its acceleration will be, and therefore the greater the change in its velocity.

Question 5: Can acceleration proportional to velocity ever be negative?

Yes, acceleration proportional to velocity can be negative. This occurs when an object is slowing down or decelerating. In this case, the acceleration and velocity are in opposite directions, resulting in a negative value for the acceleration.

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