Which substance has the least density? A. an iceberg B. a gallon of water C. a block of aluminum D. a small piece of lead

After the discovery of Uranus, astronomers calculated its orbit and predicted its position in the sky using Kepler's laws of pla

Softa [21]

Answer:

a. verify that your observations are correct

c. think about what else might cause the observed discrepancy

Explanation:

Let's begin by explaining that a law is an affirmation (something established) based on repeated long-term observation of a phenomenon that has been studied and verified.

That is: A law is present in all known theories and therefore is considered universal. In addition, <u>a law can not be refuted, nor changed, because its precepts have been proven through various studies.</u>

Then, based on what is explained above, Kepler's laws of planetary motion exist because they were rigorously tested and verified, therefore they can not be refuted.

So, if we have a small discrepancy between the predicted and actual positions of Uranus after using Kepler's laws, we have to verify carefully our observations again and search what might be causing that discrepancy. But we cannot assume Kepler's Laws are incorrecto or need modifications.

In addition, we cannot consider that Uranus may not be a planet, because the discrepancy is small. In fact, this discrepancy lead to the discovery of another planet, Neptune.

7 0

3 years ago

A rocket moves upward, starting from rest with an acceleration of 29.4 m/s^2 for 3.98 s. it runs out of fuel at the end of 3.98

ValentinkaMS [17]

The distance d₁ it rises from rest while the engine is burning is given by
d₁ = d₀ + v₀t + (1/2)at²
d₁ = 0 + 0 + (1/2)·(29.4 m/s²)·(3.98 s)² = 232.85 m
So it gets to 232.85 m and then runs out of fuel. Its velocity v₁ at this point is given by
v₁ = v₀ + at = (29.4 m/s²)·(3.98 s) = 117 m/s
At this point, gravity begins to slow it down until it reaches its peak where its velocity v₂ is zero.
v₂² = v₁² + 2ad₂
where d₂ is the distance it rises until v=0
Since gravity is decelerating the rocket, a = -g, and we have
0² = (117 m/s)² + 2(-9.8 m/s²)d₂
0 = (117)² - (19.6)·d₂
0 = 13,689 - (19.6)·d₂
d₂ = 13,689/19.6 = 698.42 m
So the total height it rises is given by
d₁ + d₂ = 232.85 m + 698.42 m
= 931.27 m

5 0

3 years ago

A singly charged positive ion has a mass of 3.46 × 10−26 kg. After being accelerated through a potential difference of 215 V the

jasenka [17]

Answer:

1.8 cm

Explanation:

$m$ = mass of the singly charged positive ion = 3.46 x 10⁻²⁶ kg

$q$ = charge on the singly charged positive ion = 1.6 x 10⁻¹⁹ C

$\Delta V$ =Potential difference through which the ion is accelerated = 215 V

$v$ = Speed of the ion

Using conservation of energy

Kinetic energy gained by ion = Electric potential energy lost

$(0.5) m v^{2} = q \Delta V\\(0.5) (3.46\times10^{-26}) v^{2} = (1.6\times10^{-19}) (215)\\(1.73\times10^{-26}) v^{2} = 344\times10^{-19}\\v = 4.5\times10^{4} ms^{-1}$

$r$ = Radius of the path followed by ion

$B$ = Magnitude of magnetic field = 0.522 T

the magnetic force on the ion provides the necessary centripetal force, hence

$qvB = \frac{mv^{2} }{r} \\qB = \frac{mv}{r}\\r =\frac{mv}{qB}\\r =\frac{(3.46\times10^{-26})(4.5\times10^{4})}{(1.6\times10^{-19})(0.522)}\\r = 0.018 m \\r = 1.8 cm$

5 0

3 years ago

The motion of a pendulum for which the maximum displacement from equilibrium does not change is an example of simple harmonic mo

Alexeev081 [22]

The statement "<span>The motion of a pendulum for which the maximum displacement from equilibrium does not change is an example of simple harmonic motion." is true.

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.
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6 0

3 years ago

Read 2 more answers

I need help in my physics class and show me how it’s done

Korolek [52]

If we have the angle and magnitude of a vector A we can find its Cartesian components using the following formula

$A_x = |A|cos(\alpha)\\\\A_y = |A|sin(\alpha)$

Where | A | is the magnitude of the vector and $\alpha$ is the angle that it forms with the x axis in the opposite direction to the hands of the clock.