A remote control car starts moving in a straight line from a fixed point. The velocity in metres per second is given by the formula
v = 3t2 - 4t - 8
i) what is the initial acceleration?
So for this question I assume you differentiate, to get your acceleration equation: a = 6t - 4
Then I'd assume you put the t at 0, to get the initial acceleration, because that is what initial means - at time 0. But that just gives me -4 acceleration, which doesn't seem right to me.
ii) how far does the car travel in the third second?
I'd assume you integrate, on this one, because you want the distance formula: d = t3 - 2t2 - 8t + c
The answer I got from this was that the constant was 15, because I set the letter t to 3, and, yup.
But then, the distance turned out to equal, um, 0. Which also didn't seem right.
What am I doing wrong, in both questions, that I end up with these weird answers??