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3 years ago

To a nighttime observer on Earth, how many degrees do the stars appear to move around Polaris in 3 hours?

1 answer:

5 0

<span>The correct answer is 45 degrees. 360 degrees is 24 hours, because it takes a whole day for the earth to turn in one whole circle. So, to find how many degrees the stars seem to move per hour, simply divide the total number of degrees by the total number of hours in a day: 360/24 = 15. Since the question is asking how much the stars appear to move in 3 hours, now multiply the number of degrees per hour times 3: 15 x 3 = 45. </span>

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Scientific theories are explanations for naturally occurring events or phenomena. Although scientific theories require extensive

Arada [10]

The answer should be B) Scientific theories and laws develop from the acquisition of scientific knowledge. Hope this helps you.

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3 years ago

Read 2 more answers

What are three (3) things you can do before exercise or sports that will keep you safe?

zaharov [31]

Answer: Drink water, practice, do some light stretches

Explanation:

3 0

3 years ago

A 10-kg package drops from chute into a 25-kg cart with a velocity of 3 m/s. The cart is initially at rest and can roll freely w

amid [387]

Answer:

(a) the final velocity of the cart is 0.857 m/s

(b) the impulse experienced by the package is 21.43 kg.m/s

Explanation:

Given;

mass of the package, m₁ = 10 kg

mass of the cart, m₂ = 25 kg

initial velocity of the package, u₁ = 3 m/s

initial velocity of the cart, u₂ = 0

let the final velocity of the cart = v

(a) Apply the principle of conservation of linear momentum to determine common final velocity for ineleastic collision;

m₁u₁ + m₂u₂ = v(m₁ + m₂)

10 x 3 + 25 x 0 = v(10 + 25)

30 = 35v

v = 30 / 35

v = 0.857 m/s

(b) the impulse experienced by the package;

The impulse = change in momentum of the package

J = ΔP = m₁v - m₁u₁

J = m₁(v - u₁)

J = 10(0.857 - 3)

J = -21.43 kg.m/s

the magnitude of the impulse experienced by the package = 21.43 kg.m/s

(c)

the initial kinetic energy of the package is calculated as;

$K.E_i = \frac{1}{2} mu_1^2\\\\K.E_i = \frac{1}{2} \times 10 \times (3)^2\\\\K.E_i = 45 \ J\\\\$

the final kinetic energy of the package;

$K.E_f = \frac{1}{2} (m_1 + m_2)v^2\\\\K.E_f = \frac{1}{2} \times (10 + 25) \times 0.857^2\\\\K.E_f = 12.85 \ J$

the fraction of the initial energy lost;

$= \frac{\Delta K.E}{K.E_i} = \frac{45 -12.85}{45} = 0.71$

7 0

3 years ago

PLEASE ANSWER ASAP!!!

Mice21 [21]

The total momentum of the system has to be conserved to satisfy the principle of conservation of momentum. Before the ball hits the bottle, the momentum of the system is 0.4 x 18 = 7.2 kg m/s

The momentum of the bottle after being hit is 0.2 x 25 = 5 kg m/s

So the momentum of the ball now is 7.2 - 5 = 2.2 kg m/s

Hence its velocity is 2.2/0.4 = 5.5 m/s

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3 years ago

The speed of an object and the direction in which it moves constitute a vector quantity known as the velocity. an ostrich is run

Orlov [11]

Velocity of an object is its rate of change of the object's position per interval of time. Velocity is a vector quantity which means that it consists of a magnitude and a direction. Magnitude is represented by the speed and the direction is represented by the angle. To determine the velocity components, we use trigonometric functions to determine the angle of the components. For the north component we, use the sine function while, for the west component, we use the cosine function. We calculate as follows:
north velocity component = (16.8 m/s) (sin 54°) = 16.4 m/s
<span>west velocity component = (16.8 m/s) (cos 54°) = 3.49 m/s</span>

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3 years ago