Determining initial velocity and instant velocity

AI Thread Summary
The discussion focuses on calculating the initial velocity (v0x) of a particle with a given acceleration function, ax(t) = 2.90t - 2.06, to ensure it has the same x-coordinate at t = 4.06 as at t = 0. The equations for velocity and position are established, integrating the acceleration to find expressions for vx and x. The user struggles with incorporating the specific time values into the equations to find v0x. The solution involves equating the position expressions at t = 0 and t = 4.06 and solving for v0x. The thread emphasizes the importance of correctly applying integration and substitution in kinematic equations.
Norfonz
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Homework Statement



The acceleration of a particle is given by ax(t) = 2.90t - 2.06

Q. Find the initial velocity v0x such that the particle will have the same x-coordinate at time t = 4.06 as it had at t = 0.

Homework Equations



vx = v0x + \intaxdt evaluated from 0 to t.
x = x0 + \intvxdt evaluated from 0 to t.

This is defined for straight-line motion with varying acceleration, which appears to fit my scenario.

The Attempt at a Solution



vx = v0x + \int(2.90t - 2.06)dt evaluated from 0 to t.
vx = v0x + 1.45t2 - 1.03t

x = x0 + \int(v0x + 1.45t2 - 1.03t)dt evaluated from 0 to t.
x = x0 + \int(1.45t2 - 1.03t)dt + v0x\intdt

x = x0 + v0xt + (1.45t3/3) - (1.03t2/2)

Unfortunately this is as far as I got. I don't understand how to incorporate the values I was given for t. Could someone point me in the right direction please?
 
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Norfonz said:
x = x0 + v0xt + (1.45t3/3) - (1.03t2/2)

Unfortunately this is as far as I got. I don't understand how to incorporate the values I was given for t. Could someone point me in the right direction please?

Well from where, when t=4.06, what is x equal to ? (in terms of v0x and x0)

And when t=0, what is x equal to ? (in terms of v0x and x0)


Then just put those equal to each other and solve for v0x
 
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