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2 years ago

Two students are talking in the corridor you can hear them in your class but you cannot see them why?

Physics

1 answer:

BaLLatris [955]2 years ago

4 0

You can hear two students talking in the corridor first, then see them due to the speed of sound.

The speed of sound is the distance that sound energy will propagate per unit of time through a medium. At room temperature, the speed of sound in air is about 1125 ft/s (343 m/s).

The speed of sound varies from substance to substance in function of the material density, elasticity and temperature. Typically sound travels most slowly in gases (like air 343 m/s), faster in liquids (like water 1481 m/s) and fastest in solids (like iron 5120 m/s).

<h3>What is velocity?</h3>

It is a physical quantity that indicates the displacement of a mobile per unit of time, it is expressed in units of distance per time, for example (miles/h, km/h).

Learn more about velocity at: brainly.com/question/3004254

#SPJ4

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The amusement park ride shown above takes riders straight up a tall tower and then releases an apparatus holding seats. This app

Natasha2012 [34]

The gravitational force on the rider is:

- Way up: equal to mg

- Way down: equal to mg

Explanation:

The choices are missing: find them in the attached figure.

The force of gravity acting on a body is a force directed downward (towards the Earth's centre) and whose magnitude is

$F=mg$

where

m is the mass of the body

g is the acceleration due to gravity

The value of g is approximately constant near the Earth's surface and it is

$g=9.8 m/s^2$

During the ride, the mass of the rider, m, remains constant. This means that the magnitude of the gravitational force, mg, exerted on the rider remains constant during the rider.

Therefore, the correct answer is

- Way up: equal to mg

- Way down: equal to mg

Learn more about force of gravity:

brainly.com/question/1724648

brainly.com/question/12785992

#LearnwithBrainly

7 0

4 years ago

When the engineer first sees the car, the locomotive is 100m from the crossing and its speed is 30m/s. If the engineer reaction

shusha [124]

Answer:

The deceleration must have the engineer to avoid the accident is

a=-5.238 $\frac{m}{s^{2} }$

Explanation:

$x_{0}=100m\\v_{0}=30 \frac{m}{s} \\t=0.47 s$

While the engineer reacts the train continue moving so

$x_{f} = v*t= 30\frac{m}{s} *0.47s= 14.1 m$

$x_{t}= x_{o}+x_{f}\\x_{t}= 100m-14.1m=85.9m$

Now the final velocity have to be zero so using equation can find deceleration

$V_{f} ^{2} =V_{o} ^{2}+2*a*x_{f}\\ 0= V_{o} ^{2}+2*a*x_{f}\\a=-\frac{V_{o} }{2*x_{f}}\\a=-\frac{(30\frac{m}{s}) ^{2} }{2*85.9m} \\a=-5.238 \frac{m }{s^{2} } } \\$

4 0

4 years ago

A billiard ball moving at 6.00 m/s strikes a stationary ball of the same mass. After the collision, the first ball moves at 5.12

Nadusha1986 [10]

Answer:

Magnitude : 3.14 m/s

Direction : 301.31 deg

Explanation:

Assuming that the ball moves in positive x-direction initially.

$m$ = mass of each ball

$\underset{v_{1i}}{\rightarrow}$ = initial velocity of first ball before collision = $6\hat{i} + 0\hat{j}$

$\underset{v_{2i}}{\rightarrow}$ = initial velocity of second ball before collision = $0\hat{i} + 0\hat{j}$

$\underset{v_{1f}}{\rightarrow}$ = final velocity of first ball after collision = $5.12 Cos31.5\hat{i} + 5.12 Sin31.5\hat{j}$

$\underset{v_{2f}}{\rightarrow}$ = final velocity of second ball after collision = ?

Using conservation of momentum

$m$ $\underset{v_{1i}}{\rightarrow}$ + $m$ $\underset{v_{2i}}{\rightarrow}$ = $m$ $\underset{v_{1f}}{\rightarrow}$ + $m$ $\underset{v_{2f}}{\rightarrow}$

( $6\hat{i} + 0\hat{j}$ ) + ( $0\hat{i} + 0\hat{j}$ ) = ( $5.12 Cos31.5\hat{i} + 5.12 Sin31.5\hat{j}$ ) + $\underset{v_{2f}}{\rightarrow}$

$\underset{v_{2f}}{\rightarrow}$ = ( $6\hat{i} + 0\hat{j}$ ) - ( $5.12 Cos31.5\hat{i} + 5.12 Sin31.5\hat{j}$ )

$\underset{v_{2f}}{\rightarrow}$ = $1.63\hat{i} - 2.68\hat{j}$

magnitude of final velocity of second ball is given as

magnitude = sqrt((1.63)² + (- 2.68)²) = 3.14 m/s

Direction is given as

θ = 360 + tan⁻¹(- 2.68/1.63)

θ = 301.31 deg

8 0

4 years ago

When planning an experiment, a scientist must first choose a question to investigate. In an experiment, Renata changes the relea

dangina [55]

Answer:

The correct option is D

Explanation:

In the course of the experiment, two key phrases/variables defined the experiment done,

i) the release height of the steel ball (independent variable)

ii) the distance the ball travels from the ramp before falling to the ground (dependent variable)

The only option that contains and relates this two variables as carried out during the course of the experiment is option D.

6 0

3 years ago

Explain how the law of conservation of energy applied to the energy transformations that occur from the outlet charger to the ri

Stels [109]

Answer: ELECTRICAL ENERGY to CHEMICAL ENERGY to SOUND ENERGY.

Explanation:

There are laws governing the conservation of energy in physics. The first law of thermodynamics states that in a closed system, energy can neither be created nor destroyed during transformation. With this, the total energy of a given system always remains constant.

This first law of thermodynamics which arouse from special relativity, says that changes in the energy of systems will also coincide with changes in a measure of its energy content.

The ELECTRICAL energy from the outlet charger is transformed and stored as CHEMICAL energy in the battery of the phone. This in turn is converted to SOUND energy when the phone rings.

6 0

3 years ago