Answer:
4.36
8.23
Step-by-step explanation:
Answer:

Step-by-step explanation:
A=b^2+2bh
b = 3
A = 3^2 + 2(3)h
A = 9 + 6h
6h = A - 9

Answer: the bridge is 11.025 m high
Step-by-step explanation:
Given that;
Time taken to hit the water t = 1.5 sec
height of bridge = ?
lets take a look at the equation of motion;
y(t) = y₀ + (1/2)at²
with initial velocity zero and we know that acceleration due to gravidity is 9.8m/s
we substitute
y(t) = (1/2)gt² = (1/2) × 9.8 × (1.5)²
y(t) = (1/2)gt² = (1/2) × 9.8 × (1.5)²
y(1.5) = 11.025 m
Therefore, the bridge is 11.025 m high
Answer:
The cost is minimized for
and then
and the ratio height / radius = 2.3
Step-by-step explanation:
When you solve these kind of problems you always need to ask yourself what am I minimizing or maximizing, for this case you need to minimize the cost function.
Suppose that the bottom of your drum has a radius
and a height and a height
then the are of the circle at the bottom would be

And the area of the sides would be given by

According to what they say the cost of the sides is 2$ per square meter and the cost of the bottom is 3$ per square meter.
So the cost would be given by this function.
Cost =
But they mention that the volume = 2 cubic meters. On the other hand
Volume =
= 2 if we replace on Cost we get that

When you find the derivative of that and equal to zero you will find that the the cost is minimized for
and then
and the ratio height / radius = 2.3