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anyanavicka [17]

3 years ago

11

Explain how a thumbtack is designed so that you do not have to use a lot of force to push it through paper or the surface of a b

ulletin board?

1 answer:

Brums [2.3K]3 years ago

8 0

Thumbtacks have a flat top which gives you a bigger area to push on, and the end is tapered and sharp to make it easier to push it into a wall, etc.

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The gravitational force of a star on an orbiting planet 1 is f1. planet 2, which is three times as massive as planet 1 and orbit

Margaret [11]

Let us consider two bodies having masses m and m' respectively.

Let they are separated by a distance of r from each other.

As per the Newtons law of gravitation ,the gravitational force between two bodies is given as - $F = G\frac{mm'}{r^{2} }$ where G is the gravitational force constant.

From the above we see that F ∝ mm' and $F\alpha \frac{1}{r^{2} }$

Let the orbital radius of planet A is $r_{1}$ = r and mass of planet is $m_{1}$ .

Let the mass of central star is m .

Hence the gravitational force for planet A is $f_{1} =G \frac{m_{1}*m }{r^{2} }$

For planet B the orbital radius $r_{2} =2r_{1}$ and mass $m_{2} = 3 m_{1}$

Hence the gravitational force $f_{2} =G\frac{m m_{2} }{r^{2} }$

$f_{2} =G\frac{m*3m_{1} }{[2r_{1}] ^{2} }$

$= \frac{3}{4} G\frac{mm_{1} }{r_{1} ^{2} }$

Hence the ratio is $\frac{f_{2} }{f_{1} } = \frac{\frac{3}{4}G mm_{1/r_{1} ^2} }{Gmm_{1}/r_{1} ^2 }$

$=\frac{3}{4}$ [ ans]

3 0

3 years ago

Read 2 more answers

Derive the explicit rule for the pattern <br> 3, 0, -3, -6, -9,

pickupchik [31]

It is the last number minus 3

8 0

3 years ago

Read 2 more answers

What is mean by combination reaction ?

mrs_skeptik [129]

$\underline{\purple{\large \sf Combination \: reaction :-}}$

Those reaction in which two or more substances combine to form a one new substance are called Combination reaction

In this reaction, We can add :

Two or more elements can combine to form a compound.
Two or more compounds can combine to from a one new compound.
An element and a compound can combine to form a new compound.

$\underline{\green{\large \sf For\: example :}}$

$\sf 2H_{2} + O_{2} \: \underrightarrow{Combination} \: 2H_{2}o$

In this, Hydrogen is an element and Oxygen is another element. Both are combined to form compound 'Hydrogen oxide'. Hydrogen oxide is commonly known as water.

3 0

3 years ago

3. How does the wavelength of green different from violet-indigo?

grandymaker [24]

Answer:

As the full spectrum of visible light travels through a prism, the wavelengths separate into the colors of the rainbow because each color is a different wavelength. Violet has the shortest wavelength, at around 380 nanometers, and red has the longest wavelength, at around 700 nanometers.

Explanation:

6 0

2 years ago

Technician A says that the accumulator is on the high-pressure side of the refrigerant system. Technician B says that the receiv

pychu [463]

Question:

The options are

a. Technician A only

b. Technician B only

c. Both A and B

d. Neither A nor B

Answer:

The correct option is

d. Neither A nor B

Explanation:

Here, we note that to locate the receiver/driers we look at the high-pressure side of refrigerant system normally around the tubes in between the expansion valve outlet and the condenser outlet and connected to the condenser.

While the accumulator can be found, attached to the evaporator outlet within the low pressure side of the refrigerant system.

Therefore, neither Technician A nor B is correct.

6 0

3 years ago