1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
alexandr1967 [171]
2 years ago
15

Why is polaris used as a celestial reference point?

Physics
1 answer:
ser-zykov [4K]2 years ago
8 0

At the equator, the North Celestial and South Celestial Poles would lie on the horizon where the meridian intersects the horizon. Polaris is called the "North Star." ... Polaris is special because the Earth's North Pole points almost exactly towards it.

You might be interested in
1) draw a simple circuit with a voltage source and four resistors wired in series
Norma-Jean [14]

Answer:

1)

In this circuit (see attachment #1), we have:

- A voltage source: in this case, we choose a battery. A voltage source is a device producing an electromotive force (in a battery, this is done by means of a chemical reaction), which is responsible for "pushing" the electrons along the circuit and creating a current. The electromotive force (emf) of the battery is also called voltage, and it is indicated with the letter V.

- Four resistors: a resistor is a device which opposes to the flow of current. The property that describes by "how much" the resistor "opposes" to the flow of current is called "resistance", and it is indicated with the letter R.

- In this circuit, the 4 resistors are in series. Resistors are said to be in series when they are connected along the same branch of the circuit, so that the same current flow across each of them.

- For resistors in series, the equivalent resistance of the circuit is given by the sum of the individual resistances:

R=R_1+R_2+...+R_n

2)

In this circuit (see attachment #2), we have:

- A voltage source: as before, we have chosen a battery, providing an electromotive  force to the circuit

- Three resistors wired in parallel. Resistors are said to be connected in parallel when they are connected along different branches, but with their terminals connected to the same point, so that each of them has the same potential difference across it.

- For resistors in parallel, the equivalent resistance of the circuit is calculated using the formula:

\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}+...+\frac{1}{R_n}

3)

In this circuit (see attachment #3), we have:

- A voltage source (again, we have choosen a battery)

- Three resistors, of which:

-- 2 of them are connected in parallel with each other

-- the 3rd one it is in series with the first two

If we call R_1,R_2 the resistances of the first 2 resistors in parallel, their equivalent resistance is:

\frac{1}{R_{12}}=\frac{1}{R_1}+\frac{1}{R_2}\\\rightarrow R_{12}=\frac{R_1 R_2}{R_1+R_2}

Then, these two resistors are connected in series with resistor R_3; and so, the total resistance of this circuit will be:

R=R_{12}+R_3=\frac{R_1R_2}{R_1+R_2}+R_3=\frac{R_1R_2+R_3(R_1+R_2)}{R_1+R_2}

4)

In this circuit (see attachment #4), we have:

- A voltage source (again, a battery)

- We have 6 resistors, which are arranged as follows:

-- Two branches each containing 3 resistors

-- The two branches are in parallel with each other

So, the total resistance of the two branches are:

R_{123}=R_1+R_2+R_3

R_{456}=R_4+R_5+R_6

And since the two branches are in parallel, their total resistance will be:

\frac{1}{R}=\frac{1}{R_{123}}+\frac{1}{R_{456}}\\\rightarrow R=\frac{R_{123}R_{456}}{R_{123}+R_{456}}=\frac{(R_1+R_2+R_3)(R_4+R_5+R_6)}{R_1+R_2+R_3+R_4+R_5+R_6}

4 0
3 years ago
A 600‑kg car accelerates at a rate of 3 m/s2. How much net force is acting on the car to cause this acceleration?
finlep [7]
600(kg) x 3(m/s^2) = 1800N (newtons)
4 0
3 years ago
Blake stands in a canoe in the middle of a lake. The canoe is stationary. Blake holds an anchor mass of 15 kg, then throws it we
Inessa05 [86]

The velocity of the canoe is  1.7 m/s.

<h3>What is momentum?</h3>

Momentum in physics is the products of mass and velocity. Now we have to find momentum with the formula; p = mv

a) Initial momentum = (15)8 m/s + 135 = 255 Kgms-1

b) Since momentum is conserved, the total momentum after throwing the anchor is still 255 Kgms-1

c) The final velocity of the boat is obtained from;

255 Kgms-1 = (15Kg + 135 Kg) v

v = 255 Kgms-1/(15Kg + 135 Kg)

v = 1.7 m/s

Learn more about momentum: brainly.com/question/904448

5 0
2 years ago
I NEED some help please!
andrew11 [14]
Fhfjhfjikauijpoejfdjkkjff\

3 0
3 years ago
Calculate the rate of heat generation in kW due to the burning of the fuel when you drive a car rated at 34 MPG (miles per gallo
alexira [117]

Answer:

Explanation:

Let us calculate gallon used in one hour .

It travels 70 miles in one hour

in 70 miles it uses 70 / 34 gallons of fuel

70 / 34 gallons = 70 / 34 x 3.7854 kg

= 7.8 kg

heat generated = 7.8 x 44 x 10⁶ J

= 343.2 x 10⁶ J

This is heat generated in one hour

heat generated in one second = 343.2 x 10⁶ / 60 x 60 J/s

= 95.33 x 10³ J /s

= 95.33 kW.

4 0
3 years ago
Other questions:
  • a spherical mirror is cut in half horizontally will an image be formed by the bottom half of the mirror how
    11·1 answer
  • Wave A has a wavelength of 2 meters and a frequency of 1.5 Hz . calculate the wave's speed
    9·1 answer
  • I drop an egg from a certain distance and it takes the egg 3.74 seconds to reach the ground. How high up was the egg?
    15·1 answer
  • Two circuits have identical voltage sources. The only other elements in the circuits are resistors. The resistor in circuit A ha
    12·1 answer
  • The coordinates of a bird flying in the xy plane are given by x(t)=αt and y(t)=3.0m−βt2, where α=2.4m/s and β=1.2m/s2. Calculate
    5·2 answers
  • Consider a loop of wire whose plane is horizontal and that carries a current in the clockwise direction when viewed from above.
    13·1 answer
  • Ms. Howard's science class looked at the group of stars called the Big Dipper, They watched it in the early evening during fall
    7·1 answer
  • what is the transfer of heat energy by direct contact. A . convection b. radiation c. thermal or heat and d. conduction ​
    9·2 answers
  • The acceleration due to gravity is higher on juniper Than on earth. The mass and weight of rock on juniper compared to that on e
    6·1 answer
  • . A certain sample of metal has a mass of 3 kg and a volume of 250 cm3. What is its density?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!