# Need help solving an equation of motion of type m x'' = F(t)

• January 31st 2013, 08:51 AM
dom139
Need help solving an equation of motion of type m x'' = F(t)
A particle of mass 3 kg, initially at position y(0) = 2 and moving with velocity v(0) = 4) is subject to the exponential driving force F(t) = 2e^(-3t)
Find an expression for y(t).
Any help would be greatly appreciated :)
• January 31st 2013, 12:30 PM
topsquark
Re: Need help solving an equation of motion of type m x'' = F(t)
$m x" = F(t) = 2e^{-3t}$

So
$x" = \frac{1}{m} \cdot 2e^{-3t}$

What is the integral of $e^{-3t}$ ?

-Dan