The number of sound waves per unit time is called what

A square-based shipping crate is being designed that must contain a volume of 16 ft3 . The material that is used for the base an

Vlada [557]

Answer:

Explanation:

Given

volume $V=16 ft^3$

Suppose base is square with side L

height of crate is h

Volume $V=L^2\times h$

$16=L^2\times h$

Cost of top and bottom area $c_1=3L^2$

Cost of Side area $c_2=4Lh\times 2=8Lh=8L\times \frac{16}{L^2}=\frac{128}{L}$

Total Cost $C=c_1+c_2$

Total Cost $C=3L^2+\frac{128}{L}$

Differentiate C w.r.t Length

$\frac{dC}{dL}=6L-\frac{128}{L^2}$

$L^3=\frac{128}{6}$

$L=2.75 ft$

$h=\frac{16}{2.75^2}=11.46 ft$

Dimensions are $L\times L\times h=2.75\times 2.75\times 11.46$

6 0

2 years ago

If you run the 100 m track at a velocity of 5.0 m/s, what is the time needed?

Tresset [83]

100/5= 20, 20 seconds is the time needed.

8 0

2 years ago

Write a description of how carbon enters and exits a consumer, such as the deer shown in the diagram.

dedylja [7]

Answer:

Carbon moves from the atmosphere to plants. In the atmosphere, carbon is attached to oxygen in a gas called carbon dioxide (CO2). Through the process of photosynthesis, carbon dioxide is pulled from the air to produce food made from carbon for plant growth.

Carbon moves from plants to animals. Through food chains, the carbon that is in plants moves to the animals that eat them. Animals that eat other animals get the carbon from their food too.

Carbon moves from plants and animals to soils. When plants and animals die, their bodies, wood and leaves decays bringing the carbon into the ground. Some is buried and will become fossil fuels in millions and millions of years.

Carbon moves from

living things to the atmosphere. Each time you exhale, you are releasing carbon dioxide gas (CO2) into the atmosphere. Animals and plants need to get rid of carbon dioxide gas through a process called respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned. When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas. Each year, five and a half billion tons of carbon is released by burning fossil fuels. Of this massive amount, 3.3 billion tons stays in the atmosphere. Most of the remainder becomes dissolved in seawater.

3 0

2 years ago

27. (a) What magnification is produced by a 0.150 cm focal length microscope objective that is 0.155 cm from the object being vi

denpristay [2]

Answer:

magnification = - 30

overall magnification = -240

Explanation:

given data

Focal length of microscope objective f = 0.150 cm

Object distance from microscope objective do = 0.155 cm

magnification by eyepiece = 8 ×

to find out

What magnification is produced and overall magnification

solution

we consider here Image distance from microscope objective is = di

so that

Magnification produced by objective will be = - $\frac{di}{do}$

so we find here di by given equation that is

$\frac{1}{do} +\frac{1}{di} = \frac{1}{f}$ ..................1

$\frac{1}{di} = \frac{1}{0.150} - \frac{1}{0.155}$

di = 4.65 cm

so that magnification by object will be

magnification = - $\frac{di}{do}$

magnification = - $\frac{4.65}{0.155}$

magnification = - 30

and

overall magnification will be

overall magnification = magnification by objective × magnification by eyepiece ........................2

overall magnification = -30 × 8

overall magnification = -240

7 0

2 years ago

Like electric charges repel each other. Please select the best answer from the choices provided

alexdok [17]

<span>Like electric charges repel each other. TRUE
I hope this helped :)</span>

7 0

2 years ago

Read 2 more answers