Circular Motion and calculating time

AI Thread Summary
The discussion focuses on calculating time in circular motion using the formula Velocity = 2PiR/T. Participants explore various equations related to centripetal force, angular velocity, and acceleration. There is an emphasis on understanding how to derive velocity and acceleration from known values, including mass and radius. The conversation also clarifies the concept of "g" in relation to acceleration, explaining how to calculate the number of g's acting on a vehicle. Overall, the thread provides insights into solving problems related to circular motion and the relevant physics equations.
ForgottenMemo
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Homework Statement



q2.jpg



Homework Equations



Velocity =2PiR/T

Time=2PiR/V

Force Centripetal = MV^2/R

Angular Displacement/Time interval = Average Angular Velocity

Angular Velocity x Radius Of Circle Path = Linear Velocity

Average Angular Acceleration = Change In Angular Acceleration/ Time Interval

Linear Acceleration = Radius of Circular Path x Angular acceleration

Force= Mass x Acceleration



The Attempt at a Solution



How do i calculate time? Once i know that i can use this formula: Velocity =2PiR/T

Is T(Time) = 360 radians?

Im not honestly sure where to start, I've been trying for 4 days now, constantly seeking infomation while at work.
 
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ForgottenMemo said:
How do i calculate time? Once i know that i can use this formula: Velocity =2PiR/T
Wouldn't it perhaps be easier to use a different formula, one in which you know all the required information?
 
Hootenanny said:
Wouldn't it perhaps be easier to use a different formula, one in which you know all the required information?


What do you mean.

1) Transpose the equation again

or

2) Theres another formula that i have missed


If so, any hint on where to look.
 
ForgottenMemo said:
What do you mean.

1) Transpose the equation again

or

2) Theres another formula that i have missed


If so, any hint on where to look.
The formula is on your list :wink:. You know the centripetal force, the mass and the radius. You want to know the velocity.
 
I so hope this is correct.

Fc= MV^2/R -> Fc x R/M=V^2

Velocity -> (1100x140)/1000 = 154^2 -> \sqrt{154} = 12.4 (m/s ?)


Acceleration -> V^2/R -> 12.4^2/140 -> 1.09 m/s^2


Force Gravity -> M x g -> 1000x9.81 = 9810g
 
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ForgottenMemo said:
I so hope this is correct.

Fc= MV^2/R -> Fc x R/M=V^2

Velocity -> (1100x140)/1000 = 154^2 -> \sqrt{154} = 12.4 (m/s ?)

Acceleration -> V^2/R -> 12.4^2/140 -> 1.09 m/s^2
I'm not checking your arithmetic, but your method looks good :approve:
ForgottenMemo said:
Force Gravity -> M x g -> 1000x9.81 = 9810g
I'm guessing by the amount of g acting on the car, they mean how many times the acceleration due to gravity is the acceleration of the car, rather than the actual force. Do you follow?
 
Would i be correct in saying that:

Acceleration x Gravity = The amount of g acting on the vehicle?

1.09 m/s^2 x 9.81 = 10.69
 
ForgottenMemo said:
Would i be correct in saying that:

Acceleration x Gravity = The amount of g acting on the vehicle?

1.09 m/s^2 x 9.81 = 10.69
Not quite. If you accelerate at 1g means you are accelerating at a rate that is equal to the acceleration due to gravity (i.e. 9.81 m.s-2). Similarly, an acceleration of 2g is equivalent to an acceleration of twice that of gravity (i.e. 19.62 m.s-2). That number of g's 'pulled' can be calculated thus:

n = \frac{a}{g}

Do you follow?
 
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Ok that would mean that.

Acceleration / Gravity = The amount of g acting on the vehicle

1.09 m/s^2 / 9.81 = 0.1 (g)
 
  • #10
ForgottenMemo said:
Ok that would mean that.

Acceleration / Gravity = The amount of g acting on the vehicle

1.09 m/s^2 / 9.81 = 0.1 (g)
Looks okay to me :approve:
 
  • #11
Hootenanny : It was a pleasure. :biggrin: Thanks for the help.
 
  • #12
ForgottenMemo said:
Hootenanny : It was a pleasure. :biggrin: Thanks for the help.
Not a problem :smile:
 
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