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3 years ago

Because of convection, the warmest air in a room

1 answer:

6 0

The correct choice is
B. rises toward the ceiling
In fact, the warmest air is also the air with least density: in warm air, the particles move faster, so the distance between them is larger, on average. Therefore, the warmest air is less dense, and because of that it tends to flow upwards (due to Archimede's principle) and it is replaced by the colder air, creating the so-called convection current.

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A car rounds a flat curve and experiences a centripetal force directed toward the center of the curve and perpendicular to the d

Usimov [2.4K]

<h2>Answer:</h2>

If a car is rounding a flat curve, it experiences a centripetal force that pulls it towards the center of the circle it is rotating in.

Now,

The centripetal force can be balanced by the centrifugal force caused due to the acceleration of the body at the high speed which counters the centripetal force and in turn prevents the car from slipping down the curve.

So,

If the car doesn't hit the gas then the car will fall down from the curve as the Centripetal force will exceed the Centrifugal force of the car.

However, if the car doesn't hit the brake then the car will maintain it's position on the flat curve track as the centrifugal force will counter the effect of centripetal force directed towards the center.

3 0

3 years ago

Read 2 more answers

Which of the following has three electrons in its valence shell? carbon aluminum sodium calcium

JulijaS [17]

Aluminum has 3 valence electrons.
You can figure out the valence electrons by looking at its group number. Aluminum is in group 3, so it has 3 valence electrons.

6 0

3 years ago

Read 2 more answers

A 2.0-mm-diameter copper ball is charged to 40 nC . What fraction of its electrons have been removed? The density of copper is 8

murzikaleks [220]

Answer:

0.02442 × 10⁻⁹

Explanation:

Given:

Diameter of copper ball = 2.00 mm = 0.002 m

Charge on ball = 40 nC = 40 × 10⁻⁹ C

Density of copper = 8900 Kg/m³

Now,

The number of electrons removed, n = $\frac{\textup{Charge on ball}}{\textup{Charge of an electron}}$

also, charge on electron = 1.6 × 10⁻¹⁹ C

Thus,

n = $\frac{40\times10^{-9}}{1.6\times10^{-19}}$

n = 25 × 10¹⁰ Electrons

Now,

Mass of copper ball = volume × density

Mass of copper ball = $\frac{4}{3}\pi(\frac{d}{2})^3$ × 8900

Mass of copper ball = $\frac{4}{3}\pi(\frac{0.002}{2})^3$ × 8900

Mass of copper ball = 0.03726 grams

Also,

molar mass of copper = 63.546 g/mol

Therefore,

Number of mol of copper in 0.03726 grams = $\frac{ 0.03726}{63.546}$

Number of mol of copper in 0.03726 grams = 5.86 × 10⁻⁴ mol

and,

1 mol of a substance contains = 6.022 × 10²³ atoms

Therefore,

5.86 × 10⁻⁴ mol of copper contains = 5.86 × 10⁻⁴ × 6.022 × 10²³ atoms.

5.86 × 10⁻⁴ mol of copper contains = 35.88 × 10¹⁹ atoms

Now,

A neutral copper atom has 29 electrons.

Therefore,

Number of electrons in ball = 29 × 35.88 × 10¹⁹ = 1023.37 × 10¹⁹ electrons.

Hence,

The fraction of electrons removed = $\frac{25\times10^{10}}{1023.37\times10^{19}}$

The fraction of electrons removed = 0.02442 × 10⁻⁹

3 0

3 years ago

Using hooke's law find the elastic constant of a spring that stretches 2 cm when 4newton force is applied to it

erica [24]

Answer:

2N/cm

Step-by-step explanation:

According to the Hooke's Law, the force required to extend or compress a spring is directly proportional distance you can stretch it, which is represented as:

$F=kx$