Engineers design a system for heating the air in a house. They want the

A child is holding a wagon from rolling straight back down in a driveway that inclined at 20 degree horizontal. if the wagon wei

Alenkinab [10]

Answer:

F = 51.3°

Explanation:

The component of weight parallel to the inclined plane must be responsible for the rolling back motion of the car. Hence, the force required to be applied by the child must also be equal to that component of weight:

$F = Parallel\ Component\ of\ Weight\ of\ Wagon= WSin\theta\\$

where,

W = Weight of Wagon = 150 N

θ = Angle of Inclinition = 20°

Therefore,

$F = (150\ N)Sin\ 20^o$

8 0

2 years ago

Where does energy originate ina food web

ValentinkaMS [17]

$\huge{\underline{\underline{\red{Answer}}}}$

In a food web the energy is originated from the SUN.

4 0

2 years ago

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Suppose you are drinking root beer from a conical paper cup. The cup has a diameter of 10 centimeters and a depth of 13 centimet

sveta [45]

Answer:

The level of the root beer is dropping at a rate of 0.08603 cm/s.

Explanation:

The volume of the cone is :

$V=\frac {1}{3}\times \pi\times r^2\times h$

Where, V is the volume of the cone

r is the radius of the cone

h is the height of the cone

The ratio of the radius and the height remains constant in overall the cone.

Thus, given that, r = d / 2 = 10 / 2 cm = 5 cm

h = 13 cm

r / h = 5 / 13

r = {5 / 13} h

$V=\frac {1}{3}\times \frac {22}{7}\times ({{{\frac {5}{13}\times h}}})^2\times h$

$V=\frac {550}{3549}\times h^3$

Also differentiating the expression of volume w.r.t. time as:

$\frac {dV}{dt}=\frac {550}{3549}\times 3\times h^2\times \frac {dh}{dt}$

Given: $\frac {dV}{dt}$ = -4 cm³/sec (negative sign to show leaving)

h = 10 cm

So,

$-4=\frac{550}{3549}\times 3\times {10}^2\times \frac {dh}{dt}$

$\frac{55000}{1183}\times \frac {dh}{dt}=-4$

$\frac {dh}{dt}=-0.08603\ cm/s$

<u>The level of the root beer is dropping at a rate of 0.08603 cm/s.</u>

3 0

2 years ago

Which of these is a benefit of nuclear energy?

Mademuasel [1]

The answer i think would be D

4 0

3 years ago

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All of the following are physical properties of hydrogen peroxide except it

tankabanditka [31]

The answer to this question is B, Reacts with sunlight.

The 2 main properties of substances are their physical properties and chemical properties.
Physical properties are some observable/measurable characteristics, such as their color, mass, state, melting point, conductivity etc.

Meanwhile, for chemical properties, they're about how the substance reacts with other substances, such as metals react with acid to form hydrogen. And by the word "react", it means there's no way turn the reaction product back to the original substance without using chemical methods such as heating or electrolysis.

Therefore, all the choices above are physical properties of hydrogen peroxide except for B, as it is the only choice that relates to the substance reacting to another substance.

5 0

3 years ago