How can I rearrange the equation to solve for time?

Thread starter einsteinette
Start date Oct 7, 2009

AI Thread Summary

To rearrange the equation d = vit + 1/2 at^2 for time (t), the solution involves using the quadratic formula. The derived formula is t = (-Vi ± √(Vi² + 2ad)) / a, where Vi is the initial velocity, a is acceleration, and d is distance. The discussion highlights that while this formula is valid, it may be more practical to use alternative equations for solving motion problems. The complexity of the derived formula can make it less appealing for quick calculations. Ultimately, understanding the context and choosing the simplest method is key in physics problem-solving.

Oct 7, 2009

einsteinette

Homework Statement

Rearrange d=vit + 1/2 at^2 for t.

The Attempt at a Solution

t = \frac{-v \pm \sqrt{v^2+4 \left( \frac{1}{2} a\right)d}}{2 \left( \frac{1}{2} a \right)}

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Oct 7, 2009

Delphi51

Homework Helper

Very hard to read that - but it looks pretty good. I get
t = (-Vi + sqrt(x))/a or (-Vi - sqrt(x))/a
where x = Vi^2 + 2*a*d
I've never seen that formula used - it is just easier to use two of the others to do the job.

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