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3 years ago

The equinox

1 answer:

7 0

The equinoxes (from Latin aequinoctium (aequus nocte), "equal night") are the times of the year when the Sun is located in the plane of the celestial equator and comes from the Latin aequinoctium (aequus nocte), "equal night". It occurs twice a year: between March 19 and 21 and between September 21 and 24 of each year. As the name implies, on the dates on which the equinoxes occur, the day lasts approximately equal to that of the night in all places on Earth.

The equinoxes are used to set the beginning of spring and autumn in each hemisphere.

Therefore the correct answer is D.

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what is the transfer of heat energy by direct contact. A . convection b. radiation c. thermal or heat and d. conduction

katrin2010 [14]

Answer:

d. conduction

Explanation:

Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.

In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.

Any material or object that allow the conduction (transfer) of electric charge or thermal energy is generally referred to as a conductor. Conductors include metal, steel, aluminum, copper, frying pan, pot, spoon etc.

In conclusion, conduction typically involves the transfer of heat energy by direct contact between two or more conductors such as a pot and electric cooker.

6 0

3 years ago

Read 2 more answers

Two carts have a compressed spring between them and are initially at rest. One of the carts has total mass, including its conten

ladessa [460]

Answer:

A) - 1.8 m/s

Explanation:

As we know that whole system is initially at rest and there is no external force on this system

So total momentum of the system must be conserved

so we will have

$m_1v_1 + m_2v_2 = 0$

now plug in all data into above equation

$5(v) + 3(3)$

$5v = -9$

$v = -1.8 m/s$

so correct answer is

A) - 1.8 m/s

3 0

4 years ago

what volume of alcohol will have the same mass as 4.2m^3 of petrol? (density of alcohol 0.4kg/m^3 and petrol is 0.3kg/m^3)

Alexxx [7]

Answer:

3.15m³

Explanation:

To solve this problem, let us first find the mass of the petrol from the given dimension.

Mass = density x volume

Volume of petrol = 4.2m³

Density of petrol = 0.3kgm⁻³

Mass of petrol = 4.2 x 0.3 = 1.26kg

So;

We can now find the volume of the alcohol

Volume of alcohol = $\frac{mass}{density}$

Mass of alcohol = 1.26kg

Density of alcohol = 0.4kgm⁻³

Volume of alcohol = $\frac{1.26}{0.4}$ = 3.15m³

7 0

3 years ago

Does this equation show that transmutation has taken place during decay?

Natalija [7]

Answer:

Maybe A is the correct answer

7 0

3 years ago

Starting from rest, a 2.1x10-4 kg flea springs straight upward. While the flea is pushing off from the ground, the ground exerts

nirvana33 [79]

Answer:

1.327363 m/s

0.00090243 m

Explanation:

u = Initial velocity

v = Final velocity

m = Mass of flea

Energy

$E=\frac{1}{2}m(v^2-u^2)\\\Rightarrow 3.7\times 10^{-4}=2.1\times 10^{-4}(v^2-0)\\\Rightarrow v=\sqrt{\frac{3.7\times 10^{-4}}{2.1\times 10^{-4}}}\\\Rightarrow v=1.32736\ m/s$

The velocity of the flea when leaving the ground is 1.327363 m/s

$W=F\times s\\\Rightarrow s=\frac{W}{F}\\\Rightarrow s=\frac{3.7\times 10^{-4}}{0.41}\\\Rightarrow s=0.00090243\ m$

The flea will travel 0.00090243 m upward

8 0

3 years ago