Answer:
173.4
Step-by-step explanation:
Surface area of the cone=pi*r*l+pi*r^2=pi*(4)*(9.8+4)=173.4
The only thing you need to do is divide 56 by -7. You know the d must be a negative number because negative x negative= positive. So 56 / -7 is -8.
Since the Power is directly proportional to the velocity, their ratio

is constant.
<span>Therefore </span>

which is a proportion:
500 : 1000 = x : 1728
that can be easily solved:
x = (500×1728)/1000 = 864kW