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4 years ago

You are holding the axle of a bicycle wheel with radius

Physics

1 answer:

erastova [34]4 years ago

6 0

Answer:

The angular acceleration of the wheel is -6.54 rad/s²

Explanation:

We'll use the equations of motion for this.

w = 2πf

f = 75 rpm = 1.25 rps = 1.25 rev/s

w₀ = initial angular velocity = 2π × 1.25 = 7.85 rad/s

w = final angular velocity = 0 rad/s

t = 1.2 s

α = ?

w = w₀ + αt

0 = 7.85 + 1.2α

α = 7.85/1.2 = - 6.54 rad/s²

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40 POINTS!! please answer the question completely and with full sentences

saveliy_v [14]

Answer:

Pure competition: This is a market that has a big amount of buyers and sellers. This is good for the consumer, because competition will cause prices to go down. Individual firms try to get their prices low enough that consumers choose them.

Monopolies: There is no potential for competition in a monopoly, because only one business or company determines prices, with no room for cross-competition. There are no examples of this because it's technically against the law, though historically in the Gilded Age people like Rockefeller and Carnegie had serious monopolies in serious industries.

Oligopolies: Oligopoly, meaning "rule of a few," is a system in which a couple of powerful companies control everything. If competition is eliminated and they cooperate with each other, consumers can be in trouble. The car market in the US is an example.

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3 years ago

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What would happen to an object in orbit without gravity pulling down?

Ksivusya [100]

Orbits only exist because of gravity.

If gravity somehow suddenly shuts off, then an object
in an orbit sails away in a straight line, in the direction
and at the speed it had when gravity disappeared.

5 0

3 years ago

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A merry-go-round of radius R, shown in the figure, is rotating at constant angular speed. The friction in its bearings is so sma

mel-nik [20]

The angular speed of the merry-go-round reduced more as the sandbag is

placed further from the axis than increasing the mass of the sandbag.

The rank from largest to smallest angular speed is presented as follows;

[m = 10 kg, r = 0.25·R]

${}$ ⇩

[m = 20 kg, r = 0.25·R]

${}$ ⇩

[m = 10 kg, r = 0.5·R]

${}$ ⇩

[m = 10 kg, r = 0.5·R] = [m = 40 kg, r = 0.25·R]

${}$ ⇩

[m = 10 kg, r = 1.0·R]

Reasons:

The given combination in the question as obtained from a similar question online are;

1: m = 20 kg, r = 0.25·R

2: m = 10 kg, r = 1.0·R

3: m = 10 kg, r = 0.25·R

4: m = 15 kg, r = 0.75·R

5: m = 10 kg, r = 0.5·R

6: m = 40 kg, r = 0.25·R

According to the principle of conservation of angular momentum, we have;

$I_i \cdot \omega _i = I_f \cdot \omega _f$

The moment of inertia of the merry-go-round, $I_m$ = 0.5·M·R²

Moment of inertia of the sandbag = m·r²

Therefore;

0.5·M·R²· $\omega _i$ = (0.5·M·R² + m·r²)· $\omega _f$

Given that 0.5·M·R²· $\omega _i$ is constant, as the value of m·r² increases, the value of $\omega _f$ decreases.

The values of m·r² for each combination are;

Combination 1: m = 20 kg, r = 0.25·R; m·r² = 1.25·R²

Combination 2: m = 10 kg, r = 1.0·R; m·r² = 10·R²

Combination 3: m = 10 kg, r = 0.25·R; m·r² = 0.625·R²

Combination 4: m = 15 kg, r = 0.75·R; m·r² = 8.4375·R²

Combination 5: m = 10 kg, r = 0.5·R; m·r² = 2.5·R²

Combination 6: m = 40 kg, r = 0.25·R; m·r² = 2.5·R²

Therefore, the rank from largest to smallest angular speed is as follows;

Combination 3 > Combination 1 > Combination 5 = Combination 6 >

Combination 2

Which gives;

[m = 10 kg, r = 0.25·R] > [m = 20 kg, r = 0.25·R] > [m = 10 kg, r = 0.5·R] > [m =

10 kg, r = 0.5·R] = [m = 40 kg, r = 0.25·R] > [m = 10 kg, r = 1.0·R].

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2 years ago

How many times hotter than the sun surface is the surface of a star the same size but gives off twice the amount of energy per s

Mila [183]

The effective temperature of a star is relative to the fourth root of the luminosity and is contrariwise proportional to the square root of the radius.

L = k R² T⁴

If the radius remains continuous, while the luminosity doubles, the temperature must increase by a factor of the fourth root of two.

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So the answer is approximately 1.19 times.

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3 years ago

In nuclear fission and fusion the mass defect is

riadik2000 [5.3K]

Option C

In nuclear fission and fusion the mass defect is the mass lost during the reaction that is converted into energy

Explanation:

Mass defect is the contrast within the estimated mass of the released system and the empirically estimated mass of the nucleus. The nuclear binding energy is acknowledged as mass, and that mass enhances "missing".

This missing mass is described as a mass defect, which is nuclear energy, also acknowledged as the mass discharged from the reaction as any trajectories. The mass defect of a nucleus depicts the mass of the energy adhesive of the nucleus and is the variation amidst the mass of a nucleus and the entirety of the masses of the nucleons of which it is comprised.

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4 years ago

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