need help with Rate of Change

[lesticles]

I don't know where to even start. I tried to differentiate but was thrown off by the 4900. I can up with 4900(-t-34)2? Could someone please help me with this?

If a tank holds 4900 gallons of water, which drains from the bottom of the tank in 34 minutes, then Torricelli's Law gives the volume V of water remaining in the tank after t minutes as
V=4900(1-(t/34))^2 0<=t<=34
Find the rate at which the water is draining from the tank after:

(A) 7 minutes .......... Rate of change =

(B) 13 minutes ........... Rate of change =

(C) 19 minutes ...........Rate of change =

 

[tkhunny]

You have V(t) = 4900(1-(t/34))^2

You need V'(t) = 4900*[2*(1-(t/34))]*(-1/34)

It's just a chain rule.