Okay, so im having problems understanding instantaneous velocity. Its not like i don't get the concept of it its just that I get stuck on where certain numbers should go in the equation. So I tried to practice some problems to help me with understanding what to do. For example, ( starting at a height of 4 feet, a ball is thrown upwards with an initial velocity of 160 feet/ sec. The ball's height after t seconds is s(t)=-16t2+160+4. Find the average velocity from t=2 to t=4.) Okay so i want to plug in the 2 and the 4 but im having trouble deciding if its the right thing to do, and i have no idea what to do with that 4 at the beginning of the equation. Do i use it or is it just there for nothing??
Im also having trouble with finding the derivative of this problem. Suppose m'(-2)=72 and m(-2)=0. Find a(-2) assuming (m/a)'(-2)=6. Okay, im not sure what to do with this either because there is more than one m. I dont know its just really confusing to me. Which one do i use? Or am i supposed to use both of them?
Subscribe to:
Post Comments (Atom)
You do plug in 2 and 4. Then you take what you got when you plugged in 4 and subtract what you got from plugging in 2. Divide that number by 4-2. That will be your answer.
ReplyDeleteis it looking for a or a'? a'(-2) is 12. I thought that was the question for that one. If not I will omit it.
ReplyDeleteWith the second question...plug all of those into the quotient rule and then since m(-2)=0 you don't need a' find a(-2) since m(a')=0
ReplyDeleteyou should end up with (72a)/(a^2)
get rid of an a then you have 72/a=6
then you finally divide 72 by 6 giving you what a(-2) equals
I'm pretty sure for the second one, B-Rob told us to omit it until she taught us in class.
ReplyDelete