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3 years ago

What does the 4 mean in the formula 4Na2SO3?

Physics

2 answers:

Lilit [14]3 years ago

8 0

Answer: 4 moles of $Na_2SO_3$

Explanation: The given compound is an ionic compound formed by combination of sodium as a metal and sulphite as polyatomic anion.

It is formed by the combination of $Na^+$ and $SO_3^{2-}$ .

Thus 1 mole of $Na_2SO_3$ contains 2 atoms of sodium, 1 atom of sulphur and 3 atoms of oxygen.

The 4 represents that 4 moles of $Na_2SO_3$ are present which contains 8 atoms of sodium, 4 atom of sulphur and 12 atoms of oxygen.

Yuri [45]3 years ago

6 0

Answer:

The '4' in front of sodium sulfate formula indicates that there are four molecules of sodium sulfate.

Explanation:

The 4 in formula $4Na_2SO_4$ is the coefficient of the compound.this 4 denoted that there are 4 molecules of sodium sulfate.

Number of sodium ion in single molecule = 2

Number of sulfate ions in single molecules = 1

Number of sodium ion in four molecule = 2 × 4 = 8

Number of sulfate ions in four molecules = 1 × 4 = 4

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Is there any induced current in the pickup coil when the polarity of the bar magnet is flipped?

stiks02 [169]

Answer:

Faraday's law , he direction of the magnetic field changes by 180º, in the polarity inversion processes, induces a voltage.

Explanation:

For this exercise let's use Faraday's law

E = - dФ / dt

Ф = B.A = B A cos θ

where B is the magnetic field, A is the area and θ is the angle between the field line and the normal to the area.

We can see that an electromotive force (voltage) is indexed when there is a variation of the field B, a variation of the area and change of the angle or when there is a combinational of them.

In this case, the magnitude of the field is constant, as the wire is rigid metal, the area is constant, but the direction of the magnetic field changes by 180º, in the polarity inversion processes, for which reason each change induces a voltage.

If a voltage is created in the ring, which has a resistance, a current is also generated in it.

Therefore the answer is If a current is created in the hoop

8 0

3 years ago

A cart is pulled by a force of 250 N at an angle of 35° above the horizontal. The cart accelerates at 1.4 m/s2. The free-body di

Vikki [24]

Answer:

Mass of the cart = 146 kg

Explanation:

A cart is pulled by a force of 250 N at an angle of 35° above the horizontal.

The cart accelerates at 1.4 m/s² horizontally.

Horizontal force = Fcosθ = 250 cos35° = 204.79N

We have F = ma

Substituting

204.79 = m x 1.4

m = 146.28 kg = 146 kg

Mass of the cart = 146 kg

3 0

3 years ago

Whats a good string length for a parachute

Yuri [45]

Answer: Hope This Helps!

Explanation:

The length of the string should be equal to the radius of the desired circle. Attaching the suspension lines: Creator of parachutes Use 4 suspension lines for each parachute. And Attatch the suspension lines onto the canopy.

3 0

3 years ago

An electrical motor spins at a constant 1975.0 rpm. If the armature radius is 7.112 cm, what is the acceleration of the edge of

stealth61 [152]

Answer:

Option D is the correct answer.

Explanation:

Since value of angular acceleration is constant, the body has only centripetal acceleration.

Centripetal acceleration

$a=\frac{v^2}{r}=\frac{(r\omega )^2}{r}=r\omega ^2$

We have radius = 7.112 cm = 0.07112 m

Frequency, f = 1975 rpm = 32.92 rps

Angular frequency, ω = 2πf = 2 x π x 32.92 = 206.82 rad/s

Substituting in centripetal acceleration equation,

$a=r\omega ^2=0.07112\times 206.82^2=3042.17m/s^2$

Option D is the correct answer.

3 0

4 years ago

a 230 kg roller coaster reaches the top of the steepest hill with a speed of 6.2 km/h. It then descends the hill, which is at an

igor_vitrenko [27]

Answer: 81.619 kJ

Explanation:

Given

Mass of roller coaster is $m=230\ kg$

It reaches the steepest hill with speed of $u=6.2\ km/h\ or \ 1.72\ m/s$

Hill to bottom is 51 m long with inclination of $45^{\circ}$

Height of the hill is $h=51\sin 45^{\circ}=36.06\ m$

Conserving energy to get kinetic energy at bottom

Energy at top=Energy at bottom

$\Rightarrow K_t+U_t=K_b+U_b\\\Rightarrow \dfrac{1}{2}mu^2+mgh=K_b+0\\\\\Rightarrow K_b=0.5\times 230\times 1.72^2+230\times 9.8\times 36.06\\\Rightarrow K_b=340.216+81,279.24\\\Rightarrow K_b=81,619.456\ J\\\Rightarrow K_b=81.619\ kJ$

8 0

3 years ago