How many known planets are in our galaxy?

A 75-kg refrigerator is located on the 70th floor of a skyscraper (300meters a over the ground) What is the potential energy of

Nata [24]

Formula for potential energy is V=mgh, where m is mass in KG, g is earth acceleration (10 m/s^2), and h its height in meters. We know mass, acceleration is constant and also known, we know height also. Lets substitute
V=75*10*300=225000[J]=225[kJ] - its the answer

7 0

3 years ago

In one type of solar energy system, sunlight heats the air within solar panels, which heats copper tubes filled with water. What

Anna71 [15]

The type of energy that is produced by the system that is described is heat energy. The correct answer is D.

3 0

3 years ago

Read 2 more answers

Now consider the statements in Part A that are inferred from models. A solar model is used to calculate interior conditions base

mafiozo [28]

Answer:

d. We can calculate it by applying Newton's version of Kepler's third law

Explanation:

The measurements of a Star like the Sun have several problems, the first one is distance, but the most important is the temperature since as we get closer all the instruments will melt. This is why all measurements must be indirect because of the effects that these variables create on nearby bodies.

Kepler's laws are deduced from Newton's law of universal gravitation, in these laws the mass of the Sun affects the orbit of the planets since it creates a force of attraction, if measured the orbit and the time it takes to travel it we can know the centripetal acceleration and with it knows the force, from where we clear the mass of the son.

Let's review the statements of the exercise

.a) False. We don't have good enough models for this calculation

.b) False. The size of the sun is very difficult to measure because it is a mass of gas, in addition the density changes strongly with depth

.c) False. The amount of light that comes out of the sun is not all the light produced and is due to quantum effects where the mass of the sun is not taken into account

.d) True. This method has been used to calculate the mass of the sun and the other planets since the variable distance and time are easily measured from Earth

Correct answer is D

6 0

3 years ago

A baton twirler is twirling her aluminum baton in a horizontal circle at a rate of 2.33 revolutions per second. A baton held hor

Nata [24]

Answer:

Explanation:

Given that;

horizontal circle at a rate of 2.33 revolutions per second

the magnetic field of the Earth is 0.500 gauss

the baton is 60.1 cm in length.

the magnetic field is oriented at 14.42°

we wil get the area due to rotation of radius of baton is

$\Delta A = \frac{1}{2} \Delta \theta R^2$

The formula for the induced emf is

$E = \frac{\Delta \phi}{\Delta t}$

$\phi = \texttt {magnetic flux}$

$E=\frac{\Delta (BA) }{\Delta t}$

$=B\frac{\Delta A}{\Delta t}$

B is the magnetic field strength

substitute

$\texttt {substitute}\ \frac{1}{2} \Delta \theta R^2 \ \ for \Delta A$

$E=B\frac{(\Delta \theta R^3/2)}{\Delta t} \\\\=\frac{1}{2} BR^2\omega$

The magnetic field of the earth is oriented at 14.42

$\omega =2.33\\\\L=60.1c,\\\\\theta=14.42\\\\B=0.5$

we plug in the values in the equation above

so, the induce EMF will be

$E=\frac{1}{2} \times (B\sin \theta)R^2\omega\\\\E=\frac{1}{2} \times (B\sin \theta)(\frac{L}{2} )\omega$

$=\frac{1}{2} \times0.5gauss\times\frac{0.0001T}{1gauss} \times\sin 14.42\times(\frac{60.1\times10^-^2m}{2} )^2(2.33rev/s)(\frac{2\pi rad}{1rev} )\\\\=2.5\times10^-^5\times0.2490\times0.0903\times14.63982\\\\=2.5\times10^-^5\times0.32917\\\\=8.229\times10^-^6V$

6 0

3 years ago

Physics question, please help?

Ludmilka [50]

0.4823 m/s

The initial velocity u1 of the ball=0

From the law of conservation of linear momentum.

m1u1+m2u2=m1v1+m2v2

(160×0)+(170×u1)=(160×0.3)+(170×0.2)

u1=0.4823m/s

6 0

3 years ago