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2 years ago

Why do the stars and the constellations in the sky appear to change positions throughout the night and throughout the year?.

1 answer:

azamat2 years ago

3 0

Answer is because of the earths rotation on its axis and it’s orbit around the sun. The earth is the one changing positions!

Reason- Diurnal motion is the scientific term referring to the assumed motion of celestial objects around Earth. This motion is actually due to the Earth's rotation on its axis and it’s orbit around the sun.

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andrezito [222]

The most i can help with is Saliva glands or salivary glands

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4 years ago

Read 2 more answers

A metal rod with a length of 22.0cm lies in the xy-plane and makes an angle of 37.9 degrees with the positive x-axis and an angl

Shtirlitz [24]

Answer:

Induced emf in the rod is, $\epsilon=0.08262\ V$

Explanation:

Given that,

Length of the rod, L = 22 cm = 0.22 m

Angle with x axis is 37.9 degrees with the positive x-axis and an angle of 52.1 degrees with the positive y-axis.

$L=0.22(cos37.9\ i)+0.22(sin37.9\ j)$

$L=(0.173\ i+0.135\ j)\ m$

Velocity of the rod, v = 6.8i m/s

Magnetic field, $B=0.170i-0.24j-0.09k$

The formula for the emf induced in the rod is given by :

$\epsilon=(v\times B){\cdot}L$

$\epsilon=(6.8i\times (0.170i-0.24j-0.09k)){\cdot} (0.173\ i+0.135\ j)$

$\epsilon=(0.612j-1.632k){\cdot}(0.173i+0.135j)$

$\epsilon=0.08262\ V$

So, the magnitude of the emf induced in the rod is 0.08262 volts. Hence, this is the required solution.

8 0

3 years ago

An Arrow (0.5 kg) travels with velocity 20 m/s to the right when it pierces an apple (2 kg) which is initially at rest. After th

sattari [20]

Answer:

4 m/s

Explanation:

From the law of conservation of momentum,

Total momentum before collision = Total momentum after collision

mu+m'u' = V(m+m')...................... Equation 1

Where m = mass of the arrow, u = initial velocity of the arrow, m' = mass of the apple, u' = initial velocity of the apple, V = Final velocity of the apple and the arrow after collision.

make V the subject of the equation

V = (mu+m'u')/(m+m').................... Equation 2

Given: m = 0.5 kg, m' = 2 kg, u = 20 m/s, u' = 0 m/s(initially at rest)

Substitute into equation 2

V = (0.5×20+2×0)/(2+0.5)

V = 10/2.5

V = 4 m/s.

Hence the final velocity of the apple and the arrow after the collision = 4 m/s

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4 years ago

A sled is pulled up to the top of a hill. At thetop of the hill the sled is released from rest and allowed to coastdown the hill

Stolb23 [73]

Answer:

a.) the speed at the bottom is greater for the steeperhill

Explanation:

since the energy at the bottom of the steeper hilis greater

$mgh =\frac{1}{mv^2}$

As we can see from above that v is higher when h ishigher.

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3 years ago

Plz do all of it i will give brainlest and thanks to best answer<br> plz do it right

Sladkaya [172]

Answer: The answer is B: Convection

Explanation: Convection transfers heat through a movement of fluids but in this case its through air hope this helps :)

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3 years ago