Answer:

Explanation:
Since
, we calculate the resistance rate by deriving this formula with respect to time:

Deriving what is left (remember that
):

So we have:

Which for our values is (the rate of <em>I(t)</em> is decreasing so we put a negative sign):

Answer:
the volume decreases at the rate of 500cm³ in 1 min
Explanation:
given
v = 1000cm³, p = 80kPa, Δp/t= 40kPa/min
PV=C
vΔp + pΔv = 0
differentiate with respect to time
v(Δp/t) + p(Δv/t) = 0
(1000cm³)(40kPa/min) + 80kPa(Δv/t) = 0
40000 + 80kPa(Δv/t) = 0
Δv/t = -40000/80
= -500cm³/min
the volume decreases at the rate of 500cm³ in 1 min
Decreases density because gases have less density than liquids