# Math Help - Somewhat physics...

1. ## Somewhat physics...

A construction worker drops a bolt while working on high-rise building 320 m above the ground. After t seconds, the bolt has fallen a distance of s metres, where s(t)= 5t^2, 0 < (or equal to) t < (or equal to) 8. The function that gives the height of the bolt above ground at time R(t)= 320-5t^2. Use this function to determine the velocity of the bolt at t= 2.

2. Originally Posted by madman1611
A construction worker drops a bolt while working on high-rise building 320 m above the ground. After t seconds, the bolt has fallen a distance of s metres, where s(t)= 5t^2, 0 < (or equal to) t < (or equal to) 8. The function that gives the height of the bolt above ground at time R(t)= 320-5t^2. Use this function to determine the velocity of the bolt at t= 2.
I have a problem with the equations. The coefficient in front of the $t^2$ in both of them is likely 0.5, not 5. Please check this.

It doesn't affect the method to solve the problem, though. The speed of the bolt will be given by the time rate of change of the distance s(t):
$s^{\prime}(t) = 2 \cdot 0.5t = t$

So at t = 2 s, the speed is 2 m/s.

-Dan