Sports car goes from a velocity of zero to a velocity of 12 m/s East in two seconds. What is the cars acceleration?

Calculate the density 1.33*10⁻⁷ gcm⁻³ into kgm⁻³.

Alex Ar [27]

1 Kg = 1,000g

Therefore 1.33 × 10^-7 g = 1.33 × 10^-10 kg

1m³ = 1,000,000cm³

Therefore 1 cm³ = 1 × 10^-6 m³

Dividing the mass per unit volume you get:

(1.33 × 10^-10 kg) ÷ (1 × 10^-6 m³)

= 1.33 × 10^(-10--6) = 1.33 × 10^(-10 + 6) = 1.33 × 10^-4 kg/m³

Density = 1.33 × 10^-4 kg/m³

5 0

3 years ago

How many electrons will a single atom of sulfur with no charge and no bonds have in its valence shell?

Svet_ta [14]

Answer:

There are 6 electrons in the outermost shell.

Explanation:

Sulphur is a non-mettalic element which is in the period 3 and group .6on the periodic table. It has an atomic number of 16 and a Mass number of 32. Atomic number tells you the number of electrons in an electrically neutral atom. It has the electronic configuration of 1s2 2s2 2p6 3s2 3p4.

The orbitals have a formula 2n^2 where n = 0, 1, 2, 3 etc.

In the shells, n = 1 so there are 2 electrons. For n = 2, 2*(2)^2 = 8 electrons. So, 16 - (8 + 2) = 6 electrons in the 3 shell (outermost shell)

Therefore from the electronic confriguration above, there are 6 electrons in the outermost shell.

6 0

3 years ago

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What is the drawback to using superconductors?

Fittoniya [83]

Answer:

Option A

The cost of keeping the semiconductor below the critical temperature is unreasonable

Explanation:

First of all, we need to understand what superconductors are. Superconductors are special materials that conduct electrical current with almost zero resistance. This means that there is little or no need for a voltage source to be connected to them. As a matter of fact, once a superconductor is connected to a power supply, one can remove the power supply and the current will still flow.

However, most superconducts can only conduct at very low temperatures up to -200 degrees Celcius. This is because, at that temperature, their atoms and molecules are relatively settled, hence they pose little or no resistance to the flow of current.

This as you can guess is extremely difficult to do, as you will need a lot of effort to cool it to that temperature and maintain it.

This makes option a the answer:

The cost of keeping the semiconductor below the critical temperature is unreasonable.

7 0

2 years ago

What's the diameter of a dish antenna that will receive 10−20W of power from Voyager at this time? Assume that the radio transmi

Murrr4er [49]

Complete Question:

The Voyager 1 spacecraft is now beyond the outer reaches of our solar system, but earthbound scientists still receive data from the spacecraft s 20-W radio transmitter. Voyager is expected to continue transmitting until about 2025, when it will be some 25 billion km from Earth.

What s the diameter of a dish antenna that will receive 10−20W of power from Voyager at this time? Assume that the radio transmitter on Voyager transmits equally in all directions(isotropically). In fact, the antenna on Voyager focuses the signal in a beam aimed at the earth, so this problem over-estimates the size of the receiving dish needed.

Answer:

d = 2,236 m.

Explanation:

The received power on Earth, can be calculated as the product of the intensity (or power density) times the area that intercepts the power radiated.

As we assume that the transmitter antenna is ominidirectional, power is spreading out over a sphere with a radius equal to the distance to the source.

So, we can get the power density as follows:

I = P /A = P / 4*π*r², where P = 20 W, and r= 25 billion km = 25*10¹² m.

⇒ I = 20 W / 4*π* (25*10¹²)² m²

The received power, is just the product of this value times the area of the receiver antenna, which we assumed be a circle of diameter d:

Pr = I. Ar =( 20W / 4*π*(25*10¹²)² m²) * π * (d²/4) = 10⁻²⁰ W

Simplifying common terms, we can solve for d:

d= √(16*(25)²*10⁴/20) = 2,236 m.

3 0

3 years ago

A baseball is hit with a bat. The direction of the ball is completely reversed and its speed is doubled. If the actual contact w

alexdok [17]

Before the impact, let the velocity of the baseball was v m/s.

After being hit by the bat its velocity is -2v
So, change in velocity, Deltav=v-(-2v)=3v
Acceleration is defined as the rate of change in velocity, i.e. actual change in velocity divided by the time taken to change it. Time taken to change velocity is the time of actual contact of the bat and ball, i.e. 0.31 s.

a=(Deltav)/(Deltat)
=(3v)/0.37
Therefore, a/v=3/0.31=9.7 s^-1
So, the ratio of acceleration of the baseball to its original velocity is 9.7.

8 0

3 years ago

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Sports car goes from a velocity of zero to a velocity of 12 m/s East in two seconds. What is the cars acceleration￼?

Sports car goes from a velocity of zero to a velocity of 12 m/s East in two seconds. What is the cars acceleration?