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3 years ago

Find the solution set of x + y = 5, 2 x - y = 7

1 answer:

4 0

X + y = 5
x = 5 - y

2x - y = 7
2(5-y) - y = 7
10 - 2y - y = 7
10 - 3y = 7
10 - 7 = 3y
3 = 3y
y = 1

x + y = 5
x + 1 = 5
x = 5 - 1
x = 4

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Which statement best describes perigee?

pantera1 [17]

Answer:

A. The closest point in the Moon's orbit to Earth

Explanation:

The perigee is defined as the closest point in the orbit of an object (such as a satellite) from the centre of the Earth. In this case, the Earth's satellite is the Moon, so the perigee is defined as the closest point in the Moon's orbit to Earth. so option A is the correct one.

Let's see instead the names of the other options:

B. The farthest point in the Moon's orbit to Earth --> this point is called apogee

C. The closest point in Earth's orbit of the Sun --> this point is called perihelion

D. The Sun's orbit that is closest to the Moon --> this point has no specific name

8 0

3 years ago

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Inside most ball-point pens is a small spring that compresses as the pen is pressed against the paper. If a force of 0.1 N compr

AnnZ [28]

Answer:

20 N/m

Explanation:

From the question,

The ball-point pen obays hook's law.

From hook's law,

F = ke............................ Equation 1

Where F = Force, k = spring constant, e = compression.

Make k the subject of the equation

k = F/e........................ Equation 2

Given: F = 0.1 N, e = 0.005 m.

Substitute these values into equation 2

k = 0.1/0.005

k = 20 N/m.

Hence the spring constant of the tiny spring is 20 N/m

8 0

3 years ago

The collision between a hammer and a nail can be considered to be approximately elastic. estimate the kinetic energy acquired by

Setler [38]

Here we can use momentum conservation as in this type of collision there is no external force on it

$m_1v_{1i} + m_2v_{2i} = m_1 v_{1f} + m_2v_{2f}$

now here we can say

$m_1 = 10 g$

$v_{1i} = 0$

$m_2 = 550 g$

$v_{2i} = 3.5 m/s$

now here we can say

$10*0 + 550 * 3.5 = 10 v_{1f} + 550 v_{2f}$

$192.5 = v_{1f} + 55 v_{2f}$

now by coefficient of restitution

for elastic collision we know that e = 1

$v_{2f} - v_{1f} = e(v_{1i} - v_{2i})$

$v_{2f} - v_{1f} = 0 - 3.5$

now by solving the two equation

$56v_{2f} = 189$

$v_{2f} = 3.375 m/s$

also we know that

$v_{1f} = v_{2f} + 3.5 = 3.375 + 3.5 = 6.875 m/s$

so final speed of the nail is 6.875 m/s

6 0

3 years ago

Read 2 more answers

_______ measures an object's change in position per unit time.

Deffense [45]

I believe your answer should be C. Speed.

6 0

3 years ago

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Which illustrates the law of conservation of matter? A. producers because they create new matter B. decomposers because they des

Klio2033 [76]

D. compost bins because they recycle matter into a new form

Explanation:

The law of conservation of matter is about the creation and how matter is being transferred. According to the law, the matter cannot be destroyed. The matter should always be transferred from one form to another in the universe. There is never destruction of matter happens. There is also one more point to it, as it cannot be destroyed it also cannot be created.
Here in the options, option A tells us the creation which is not possible, option B says about the destruction of matter which is not true according to the law, C is about storing the matter which will not happen because its get transferred and D is the correct option because it talks about the recycle/ transfer of matter.

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3 years ago