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3 years ago

I have my exam monday I need some help!

Physics

1 answer:

Lana71 [14]3 years ago

7 0

Answer:

Explanation:

If the passage of the waves is one crest every 2.5 seconds, then that is the frequency of the wave, f.

The distance between the 2 crests (or troughs) is the wavelength, λ.

We want the velocity of this wave. The equation that relates these 3 things is

$f=\frac{v}{\lambda}$ and filling in:

$2.5=\frac{v}{2.0}$ so

v = 2.5(2.0) and

v = 5.0 m/s

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A billiard ball is moving in the x-direction at 30.0 cm/s and strikes another billiard ball moving in the y-direction at 40.0 cm

ipn [44]

To solve this problem it is necessary to apply the trigonometric ratios of the given velocity components.

If we make a graph of the velocity vectors in their respective velocities according to the given description we will have something similar to the attached graph.

The angle could be obtained from the components of the opposite leg and the adjacent leg so that

$tan\theta = \frac{x}{y}$

$\theta = tan^{-1}(\frac{x}{y})$

The opposite leg value (y) is 40cm / s and the adjacent leg (x) is 30cm / s

$\theta = tan^{-1}(\frac{30}{40})$

$\theta = 36.87\°$

Therefore the final direction that does the first ball is 36.87°

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3 years ago

An alert physics student stands beside the tracks as a train rolls slowly past. He notes that the frequency of the train whistle

Dovator [93]

Answer:The velocity of the train is 3.84m/s

Explanation:

According to the Doppler effect, if the source is moving towards you then the apparent frequency of the sound emitted by the source is higher and if the source is moving away from you then the apparent frequency of the sound emitted by the source is smaller.

This is given by:

fo = V +-Vo/ V +-Vo × source

Where fo= observed frequency

V= velocity of sound

Vo= vo it of the observer

fsource= frequency the source

Given:

Observed frequency of the approaching train fo1= 452Hz

The observed frequency of train= fo2= 442Hz

Velocity of sound= 334m/s

Velocity of source=?

Train approaching the observer is given by:

fo1= V/(V - Vs)× source ...eq1

Train passes the student is given by:

fo2= V/(V - Vs)×source ...eq2

Divide eq1 by eq2

452/442 = (343+Vs)/(343 - Vs)

1.02 =(343+Vs)/(343 -Vs)

Cross multiply

1.02(343- Vs) = 343 + Vs

350.76 - 1.02Vs = 343 + Vs

Collecting like terms

350.76 -343= 1.02Vs+ Vs

7.76 = 2.02Vs

Vs= 7.76/2.02

Vs= 3.84m/s

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3 years ago

On a spending spree in Malaysia, you buy an ox with a weight of 28.9 piculs in the local unit of weights: 1 picul = 100 gins, 1

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Answer:

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Explanation:

If 1 piculs = 100 gins,

Then 28.9 piculs = (28.9 × 100) gins = 2890 gins.

Also,

If 1 gin = 16 tahils

then 2890 gins =( 16 × 2890 ) = 46240 tahils

Also,

If 1 tahil = 10 chees,

Then 46240 tahils = 46240 × 10 chees = 462400 chees.

Also,

If 1 chee = 10 hoons

Then 462400 chees =( 10 × 462400) hoons = 4624000 hoons.

Also,

If 1 hoon = 0.3779 g,

Then 4624000 hoons = 0.3779 × 4624000 = 1747409.6 g.

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3 years ago

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Novosadov [1.4K]

Answer:

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Explanation:

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Answer:

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Explanation:

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4 years ago