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3 years ago

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Which astronomer proved that the planets of our solar system move in elliptical orbits? A. Kepler B. Copernicus C. Ptolemy D. Ga

lileo

2 answers:

daser333 [38]3 years ago

5 0

The answer is A) kelper

Ierofanga [76]3 years ago

3 0

The answer is Kepler

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A dc motor with its rotor and field coils connected in series has an internal resistance of 3.2 Ω. When running at full load on

pochemuha

Answer:

The current drawn by the motor from the line is 4.68 A.

Explanation:

Given that,

Internal resistance of the dc motor, r = 3.2 ohms

Voltage, V = 120 V

Emf in the motor, $\epsilon=105\ V$

We need to find the current drawn by the motor from the line. A dc motor with its rotor and field coils connected in series, applying loop rule we get :

$V=\epsilon+Ir$

I is current drawn by the motor

$I=\dfrac{V-\epsilon}{r}\\\\I=\dfrac{120-105}{3.2}\\\\I=4.68\ A$

So, the current drawn by the motor from the line is 4.68 A. Hence, this is the required solution.

7 0

3 years ago

The parallel axis theorem relates Icm, the moment of inertia of an object about an axis passing through its center of mass, to I

erma4kov [3.2K]

Answer:

Part a)

$I_{end} = \frac{mL^2}{3}$

Part b)

$I_{edge} = \frac{2ma^2}{3}$

Explanation:

As we know that by parallel axis theorem we will have

$I_p = I_{cm} + Md^2$

Part a)

here we know that for a stick the moment of inertia for an axis passing through its COM is given as

$I = \frac{mL^2}{12}$

now if we need to find the inertia from its end then we will have

$I_{end} = I_{cm} + Md^2$

$I_{end} = \frac{mL^2}{12} + m(\frac{L}{2})^2$

$I_{end} = \frac{mL^2}{3}$

Part b)

here we know that for a cube the moment of inertia for an axis passing through its COM is given as

$I = \frac{ma^2}{6}$

now if we need to find the inertia about an axis passing through its edge

$I_{edge} = I_{cm} + Md^2$

$I_{edge} = \frac{ma^2}{6} + m(\frac{a}{\sqrt2})^2$

$I_{edge} = \frac{2ma^2}{3}$

7 0

3 years ago

A person pushes a refrigerator across a horizontal floor. The mass of the refrigerator is 110 kg, the coefficient of static fric

Law Incorporation [45]

Answer:

Explanation:

mass of refrigerator, m = 110 kg

coefficient of static friction, μs = 0.85

coefficient of kinetic friction, μk = 0.59

(a) the minimum force required to just start the motion in refrigerator

F = μs x mg

F = 0.85 x 110 x 9.8

F = 916.3 N

(b) The force required to move the refrigerator with constant speed

F' = μk x mg

F' = 0.59 x 110 x 9.8

F' = 636.02 N

(c) Let a be the acceleration.

Net force = Applied force - friction force

F net = 950 - 636.02

F net = 313.98 N

a = F net / mass

a = 313.98 / 110

a = 2.85 m/s²

4 0

3 years ago

How deep is the event horizon

Basile [38]

Explanation:

The supermassive black holes that the Event Horizon Telescope is observing are far larger; Sagittarius A*, at the center of the Milky Way, is about 4.3 million times the mass of our sun and has a diameter of about 7.9 million miles (12.7 million km), while M87 at the heart of the Virgo A galaxy is about 6 billion solar ..

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3 years ago

An object has a mass of 6kg. calculate it's gpe

m_a_m_a [10]

Explanation:

When m=<em>mass</em>

G=<em>a</em><em>c</em><em>c</em><em>e</em><em>l</em><em>e</em><em>r</em><em>a</em><em>t</em><em>i</em><em>o</em><em>n</em><em> </em><em>d</em><em>u</em><em>e</em><em> </em><em>t</em><em>o</em><em> </em><em>gravity</em>

<em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em>H</em><em>=</em><em>h</em><em>e</em><em>i</em><em>g</em><em>h</em><em>t</em>

<em>U</em><em>s</em><em>i</em><em>n</em><em>g</em><em> </em><em>f</em><em>o</em><em>r</em><em>m</em><em>u</em><em>l</em><em>a</em>

<em>M</em><em>g</em><em>h</em>

<em>(</em><em>M</em><em>=</em><em>6</em><em>, </em><em>g</em><em>=</em><em>10</em><em>,</em><em>h</em><em>=</em><em>?</em><em>) </em>

6×10×h

=60joules

7 0

3 years ago