http://www.wikihow.com/Calculate-Instantaneous-Velocity Go to website above to find out how to find instantaneous velocity
Actually, you should find v(t) first, then evaluate v(5).
v(t) = s'(t)
so v(t)= -3 + 4t^2?
You have to calculate s'(t) first. In other words, take the derivative of s(t) to get v(t).
The derivative of -3 + 4t^2 is 8t. so 8t=vt? Then what?
Now evaluate v(5).
so 8*5=40. so the instantaneous velocity is 40?