In this equation: H=-16t^2+vt+s, are there any units for the 16? I am wondering if it is 16m/sec^2.

Question

In this equation:  H=-16t^2+vt+s, are there any units for the 16?  I am wondering if it is 16m/sec^2.

anonymous · Answer

Whats the units of your other variables?

anonymous · Answer

in/sec

anonymous · Answer

which is in/sec?

Or do you mean lengths ($H$ and $s$) are inches and time ($t$) is seconds? If this is the case, then it's
$$ \frac{in}{sec^2}.$$

anonymous · Answer

We know what the velocity is (90in/sec) and we know the time to be .4sec.  The variable "s" is 3in.  We are trying to solve for H, but wonder if -16 has any units that we need to be aware of so that we get the correct answer

anonymous · Answer

-16 represents (half) acceleration, and it's always length unit per square time unit.

(sorry >.<)

anonymous · Answer

So in this case, it would be -16in/sec^2?  
We are doing a catapult problem

anonymous · Answer

Oops, I was really wrong. It needs to be in feet/sec^2 and you need to change all your other numbers to feet because the coefficient of $t^2$ is half the acceleration due to gravity, i.e. half of -32 ft/sec$^2$. Alternatively, you could convert it to -32*12 in/sec$^2$ to match your other units.