^^ help :c

Which of the following is not a natural resource? a. time b. water c. land d. air Please select the best answer from the choices

AleksAgata [21]

Answer: Option (a) is the correct answer.

Explanation:

Resources which are created by human beings are known as man-made resources.

For example, glass, rayon, nylon etc are all man-made resources.

Whereas resources which are naturally created are known as natural resources.

For example, wind, air, water etc are all natural resources.

Thus, we can conclude that out of the given options time is not a natural resource.

3 0

2 years ago

According to the Doppler Effect, which statement is true about a sound as it approaches you and then moves away.

Fiesta28 [93]

As the source approaches you, the sound waves are compressed, so
the pitch of the sound is higher than what the source is actually emitting.

Then, after it passes you and begins moving away, the sound waves
are stretched, so the pitch of the sound is lower than what the source
is actually emitting.

6 0

3 years ago

Read 2 more answers

The maximum gauge pressure in a hydraulic lift is 18.0 atm what is the largest size vehicle

victus00 [196]

There is a missing part in the question. Found the complete text on internet:
"What is the largest size vehicle (kg) it can lift if the diameter of the output line is 28.0 cm? "

Solution
The diameter of the piston is 28.0 cm, this means its radius is 14.0 cm (half the diameter), so the area of the piston is
 $A=\pi r^2 = \pi (0.14 m)^2 =6.15 \cdot 10^{-2} m^2$

The maximum pressure of the lift is
 $p=18.0 atm = 1.82 \cdot 10^6 Pa$

Therefore the maximum force the piston can lift is
 $F=pA=(1.82 \cdot 10^6 Pa)(6.15 \cdot 10^{-2} m^2)=1.12 \cdot 10^5 N$

And the size (the mass) of the vehicle is
 $m= \frac{F}{g}= \frac{1.12 \cdot 10^5 Pa}{9.81 m/s^2} =1.14 \cdot 10^4 kg$

3 0

2 years ago

A book on a 2-meter high shelf has a mass of 0.4 kg. What is its potential energy?

poizon [28]

Answer:

$\boxed {\boxed {\sf 7.84 \ Joules}}$

Explanation:

The formula for potential energy is:

$PE=m*g*h$

where m is the mass, g is the gravitational acceleration, and h is the height.

The mass of the book is 0.4 kilograms. The gravitational acceleration on Earth is 9.8 m/s². The height of the book is 2 meters.

$m=0.4 \ kg \\g=9.8 \ m/s^2 \\h=2\ m$

Substitute the values into the formula.

$PE=(0.4 \ kg)(9.8 \ m/s^2)(2 \ m)$

Multiply the first two numbers.

0.4 kg*9.8 m/s²= 3.92 kg*m/s²
If we convert the units now, the problem will be much easier later on.
1 kg*m/s² is equal to 1 Newton. So, our answer of 3.92 kg*m/s² is equal to 3.92 N

$PE=(3.92 \ N )(2 \ m)$

Multiply.

3.92 N* 2 m=7.84 N*m
1 Newton meter is equal to 1 Joule (this is why we converted the units).
Our answer is equal to 7.84 Joules.

$PE=7.84 \ J$

6 0

2 years ago

Read 2 more answers

Determine whether or not each of the following statement is true. If a statement is true, prove it. If the statement is false, p

Studentka2010 [4]

Answer:

True

Explanation:

This is a representation of Gauss law.

Gauss’s law does hold for moving charges, and in this respect Gauss’s law is more general than Coulomb’s law. In words, Gauss’s law states that: The net outward normal electric flux through any closed surface is proportional to the total electric charge enclosed within that closed surface. The law can be expressed mathematically using vector calculus in integral form and differential form, both are equivalent since they are related by the divergence theorem, also called Gauss’s theorem.

8 0

3 years ago