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3 years ago

PLEASE HELP URGENT

1 answer:

6 0

PLEASE ANSWER BOTH AS FAST AS POSSIBLE PLEASE HELP HELP ILL MARK BRAINLEST!!!!! PLEASE ANSWER BOTH AS FAST AS POSSIBLE PLEASE HELP HELP ILL MARK BRAINLEST!!!!! PLEASE ANSWER BOTH AS FAST AS POSSIBLE PLEASE HELP HELP ILL MARK BRAINLEST!!!!! PLEASE ANSWER BOTH AS FAST AS POSSIBLE PLEASE HELP HELP ILL MARK BRAINLEST!!!!! PLEASE ANSWER BOTH AS FAST AS POSSIBLE PLEASE HELP HELP ILL MARK BRAINLEST!!!!!

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koban [17]

The question is not well presented.

There is ______ shift in sound frequency for observers towards whom the source is approaching.

Answer:

The gap should be filled with an apparent upward

Explanation:

The Doppler effect (also referred to as the Doppler shift) is the difference in frequency of a wave when related to an observer who has a relative movement to the wave source

The Doppler effect can be observed to occur with all types of waves - most notably water waves, sound waves, and light waves

The Doppler effect describes sound as an effect which is produced from a moving source of wave.

According to the Doppler effect;

When the source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching.

3 0

4 years ago

a bus is moving with the velociity of 36 km/hr . after seeing a boy at 20 m ahead on the road, the driver applies the brake and

Klio2033 [76]

Answer:

Assumption: the acceleration of this bus is constant while the brake was applied.

Acceleration of this bus: approximately $\left(-6.0\; \rm m \cdot s^{-2}\right)$ .

It took the bus approximately $1.7\;\rm s$ to come to a stop.

Explanation:

Quantities:

Displacement of the bus: $x = 10\; \rm m$ .
Initial velocity of the bus: $\displaystyle u = 36\; \rm km \cdot hr^{-1} = 36\; \rm km \cdot hr^{-1}\times \frac{1\; \rm m \cdot s^{-1}}{3.6\; \rm km\cdot hr^{-1}} = 10\; \rm m \cdot s^{-1}$ .
Final velocity of the bus: $v = 0\; \rm m\cdot s^{-1}$ because the bus has come to a stop.
Acceleration, $a$ : unknown, but assumed to be a constant.
Time taken, $t$ : unknown.

Consider the following SUVAT equation:

$\displaystyle x = \frac{1}{2}\, \left(a\, t^2\right) + u\, t$ .

On the other hand, assume that the acceleration of this bus is indeed constant. Given the initial and final velocity, the time it took for the bus to stop would be inversely proportional to the acceleration of this bus. That is:

$\displaystyle t = \frac{v - u}{a}$ .

Therefore, replace the quantity $t$ with the expression $\displaystyle \left(\frac{v - u}{a}\right)$ in that SUVAT equation:

$\displaystyle x = \frac{1}{2}\, \left(a\, \left(\frac{v -u}{a}\right)^2\right) + u\, \left(\frac{v - u}{a}\right)$ .

Simplify this equation:

$\begin{aligned}x &= \frac{1}{2}\, \left(a\, {\left(\frac{v -u}{a}\right)}^2\right) + u\, \left(\frac{v - u}{a}\right) \\ &= \frac{1}{2}\left(\frac{{(v - u)}^2}{a}\right) + \frac{u\, (v - u)}{a} =\frac{1}{a}\, \left(\frac{{(v - u)}^2}{2} + u\, (v - u)\right)\end{aligned}$ .

Therefore, $\displaystyle a= \frac{1}{x}\, \left(\frac{{(v - u)}^2}{2} + u\, (v - u)\right)$ .

In this question, the value of $x$ , $u$ , and $v$ are already known:

$x = 10\; \rm m$ .
$\displaystyle u =10\; \rm m \cdot s^{-1}$ .
$v = 0\; \rm m\cdot s^{-1}$ .

Substitute these quantities into this equation to find the value of $a$ :

$\begin{aligned} a &= \frac{1}{x}\, \left(\frac{{(v - u)}^2}{2} + u\, (v - u)\right) \\ &= \frac{1}{10\; \rm m}\times \left(\frac{{\left(0\; \rm m \cdot s^{-1} - 10\; \rm m \cdot s^{-1}\right)}^2}{2} + \left(0\; \rm m \cdot s^{-1} - 10\; \rm m \cdot s^{-1}\right)\times 10\; \rm m \cdot s^{-1}\right)\\ &\approx -6.0\; \rm m \cdot s^{-2}\end{aligned}$ .

(The value of acceleration $a$ is less than zero because the velocity of the bus was getting smaller.)

Substitute $a \approx -6.0\; \rm m \cdot s^{-2}$ (alongside $u = 10\; \rm m \cdot s^{-1}$ and $v = 0\; \rm m \cdot s^{-1}$ ) to estimate the time required for the bus to come to a stop:

$\begin{aligned}t &= \frac{v - u}{a} \\ &\approx \frac{0\; \rm m \cdot s^{-1} - 10\; \rm m \cdot s^{-1}}{-6.0\; \rm m \cdot s^{-2}} \approx 1.7\; \rm s\end{aligned}$ .

8 0

3 years ago

Tricia puts 44 g of dry ice (solid CO2) into a 2.0-L container and seals the top. The dry ice turns to gas at room temperature (

Irina-Kira [14]

Answer:

Corect answer is D

Explanation:

Assuming that the C O 2 gas is behaving ideally, therefore, we can use the ideal gas law to find the pressure increase in the container by:

P V=nRT ⇒ P=n R T /V

n=no of moles of the gas = mass/molar mass

Molar mass o f C O 2=44g/mol, mass = 44g

mole n = 1mole

T=20C=293K

R=0.0821L.atm/mol.K

P=nRT/V

P = 1 x 0.0821 x 293/2

P = 12atm

6 0

3 years ago

What is the mass of 2.5 mol of Ca, which has a molar mass of 40 g/mol?

ipn [44]

Answer:100 g of ca

Explanation:

4 0

3 years ago

How can i calculate distances between objects by using the concepts of echo location

dangina [55]

Send wave from your location to the object and wait until echo is back.
Measure the time taken.

If you know the speed of wave (say sound wave), than just multiply by half time taken wave to return

5 0

3 years ago