Help me someone ?...

List the requirements of practical fuel?

rewona [7]

Answer:

Here we have some of the requirement of practical fuel are

1. It must contain large amount of stored energy. So that more amount of power output available to run the engines, motors etc.

2. It must occur in abundance in nature or be easy to produce.

3. The fuel must be made up of elements that combine easily with oxygen. Foe example if hydrogen molecules reacts with oxygen. Then the products are at the reaction of lower energy than the reactants, the result is the explosive release of energy and the product of water.

7 0

3 years ago

A liquid will evaporate more.....at a lower temperature

nadezda [96]

Answer:

Otherwise, as long as the air is not saturated with water vapor - which is to say that the humidity is below 100% - some evaporation can occur at any temperature when there is liquid water to evaporate. The higher the temperature, the faster evaporation takes place, and the lower the temperature, the slower evaporation takes place.

7 0

3 years ago

Use equation <img src="https://tex.z-dn.net/?f=I%3D%5Cint%20r%5E2dm" id="TexFormula1" title="I=\int r^2dm" alt="I=\int r^2dm" al

makkiz [27]

Answer:

Explanation:

Given that

I= ∫r²dm

We need to integrate over the volume of the disc, which is not smart enough, so we brake the disc into rings and integrate from the center r=0 to r=R, as shown in attachment

Since we know the moment of inertial of a ring to be

I=mr²

We cannot integrate the r² with respect to m, so we are going to write dm as a function of r

dm

So we assume that

The ratio of the area of the rings to the whole disc is equal to ratio of their masses.

dm/M=2πrdr/πR²

Therefore,

dm=2rM/R² dr

So we are going to replace dm in the integral

I= ∫r²dm

I= ∫r²(2rM/R²) dr. From 0 to R

Where 2, M and R are constant,

I= 2M/R² ∫r³dr. From r=0 to r=R

I= 2M/R² (r⁴/4) From r=0 to r=R

I=2M/R² (R⁴/4 - 0)

I=2M/R² × R⁴/4

I=MR²/2.

This is the moment of inertial of the disc and it doesn't depend on the thickness of the disc.

5 0

3 years ago

John does 3.2J of work to lower the window shade in her bedroom a distance of 0.8m. How much force must John exert on the window

Gekata [30.6K]

Answer:

$\boxed {\boxed {\sf 4 \ Newtons}}}$

Explanation:

Work is energy transferred when an object is moved. It is the product of force and distance.

$W= F*d$

John did 3.2 Joules of work or 3.2 Newton meters of work (the units are equivalent). The window shade was lowered a distance of 0.8 meters.

W=3.2 N*m
d= 0.8 m

Substitute the values into the formula.

$3.2 \ N *m = F * 0.8 \ m$

We are solving for the force, so we must isolate the variable F. It is being multiplied by 0.8 meters. The inverse operation of multiplication is division, so divide both sides of the equation by 0.8 m.

$\frac {3.2 \ N*m}{0.8 \ m}= \frac{ F* 0.8 \ m}{0.8 \ m}$