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3 years ago

Convection occurs when thermal energy is transferred by the movement of

Physics

1 answer:

madam [21]3 years ago

6 0

Answer:

Convection is the transfer of thermal energy from one place to another by the movement of gas or liquid particles. How does this happen? As a gas or liquid is heated, the substance expands. This is because the particles in liquids and gases gain kinetic energy when they are heated and start to move faster.

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In which of the following situation is light most likely to be a reflection

maxonik [38]

Answer:

when the reflecting surface is plain and without even small hurdles that are not the visible by our naked eyes. Eg : plain mirror

Explanation:

7 0

3 years ago

A flutist assembles her flute in a room where the speed of sound is 342m/s . When she plays the note A, it is in perfect tune wi

USPshnik [31]

Answer:

a.3Hz

b.0.0034m

Explanation:

First, we know the flute is an open pipe, because open pipe as both end open and a close organ pipe as only one end close.

The formula relating the length and he frequency is giving as

$f=\frac{nv}{2l}\\$ .

a.we first determine the length of the flute at the fundamental frequency i.e when <em>n</em>=1 and when the speed is in the 342m/s

Hence from

$f=\frac{nv}{2l}\\\\l=\frac{342}{2*440}\\ l=0.389m\\$ .

since the value of the length will remain constant, we now use the value to determine the frequency when the air becomes hotter and the speed becomes 345m/s.

$f=\frac{nv}{2l} \\f=\frac{345}{2*0.389}\\f=443.4Hz$

Hence the require beat is

$B=/f_{1}-f_{2}/\\B=/440-443/\\B=3Hz$ .

b. since the length is dependent also on the speed and frequency, we determine the new length when she plays with a fundamental frequency when the speed of sound is 345m/s

using the formula

$L_{new}=\frac{v}{2f}\\\\L_{new}=\frac{345}{2*440}\\\\L_{new}=0.39204$

Now to determine the extension,

$L_{extend}=L_{new}-L_{old}\\L_{extend}=0.39204- 0.38864\\L_{extend}=0.0034m\\$

4 0

3 years ago

Find the acceleration produced.

krok68 [10]

Answer:

0.67m/s²

Explanation:

Given parameters:

Mass of toy = 1.2kg

Force applied = 0.8N

Unknown:

Acceleration = ?

Solution:

According to newton's second law of motion;

Force = mass x acceleration

Now,

Acceleration = $\frac{Force}{mass}$

Acceleration = $\frac{0.8}{1.2}$ = 0.67m/s²

4 0

3 years ago

Read 2 more answers

Two cars are traveling in the same direction down a highway at 65 miles per hour. What is the relative velocity of the second ca

Levart [38]

Answer:

5 hours

Explanation:

Let the required time be x hours. The time will be the same for both cars.

The cars will cover different distances because they are travelling at different speeds.

The distance travelled by the slower car = 50×x miles.

The distance travelled by the faster car = 58×x miles.

The two distances differ by 40 miles.

58x−50x=40

8x=40

x=5 hours

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A second method:

The difference in the distances is 40 miles

The difference in the speeds is #8mph.

The time to make up the 40 miles= $\frac{40}{8}$ =5 hours

8 0

3 years ago

Two engineering students, John with a weight of 96 kg and Mary with a weight of 48 kg, are 30 m apart. Suppose each has a 0.04%

djyliett [7]

Answer:

$6.8370869499\times 10^{20}\ N$

Explanation:

$N_A$ = Avogadro's number = $6.022\times 10^{23}$

e = Charge of electron = $1.6\times 10^{-19}\ C$

k = Coulomb constant = $8.99\times 10^{9}\ Nm^2/C^2$

Z = Atomic number of water = 18

M = Molar mass of water = 0.018 kg/mol

m = Mass of person

The charge is given by

$q=imbalance\times n\times e$

Total number of protons and electrons in each sphere

$n=\dfrac{mN_AZe}{M}$

$q=imbalance\times \dfrac{mN_AZe}{M}$

$q_1=0.0004\times \dfrac{96\times 6.022\times 10^{23}\times 18\times 1.6\times 10^{-19}}{0.018}\\\Rightarrow q_1=3699916.8\ C$

$q_2=0.0004\times \dfrac{48\times 6.022\times 10^{23}\times 18\times 1.6\times 10^{-19}}{0.018}\\\Rightarrow q_1=1849958.4\ C$

Electrical force is given by

$F=\dfrac{kq_1q_2}{r^2}\\\Rightarrow F=\dfrac{8.99\times 10^{9}\times 3699916.8\times 1849958.4}{30^2}\\\Rightarrow F=6.8370869499\times 10^{20}\ N$

The electrostatic force of attraction between them is $6.8370869499\times 10^{20}\ N$

4 0

4 years ago