Laws are statements about something that's been observed and stated while a theory is an explanation of what's been observed. This connection between them forms a main idea that many people regulate as "what's normal."

Explanation:

4 0

3 years ago

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The Bullet Train The Shinkansen, the Japanese "bullet" train, runs at high speed from Tokyo to Nagoya. Riding on the Shinkansen,

jeyben [28]

Answer:

68.6 m/s

Explanation:

v = Speed of sound in air = 343 m/s

u = Speed of train

$f_1$ = Actual frequency

From the Doppler effect we have the observed frequency as

When the train is approaching

$f=f_1\frac{v+u}{v}$

When the train is receeding

$\frac{2f}{3}=f_1\frac{v-u}{v}$

Dividing the above equations we have

$\frac{f}{\frac{2f}{3}}=\frac{f_1\frac{v+u}{v}}{f_1\frac{v-u}{v}}\\\Rightarrow \frac{3}{2}=\frac{v+u}{v-u}\\\Rightarrow 3v-3u=2v+2u\\\Rightarrow v=5u\\\Rightarrow u=\frac{v}{5}\\\Rightarrow u=\frac{343}{5}\\\Rightarrow u=68.6\ m/s$

The speed of the train is 68.6 m/s

5 0

3 years ago

In order to determine the speed of an object, what measurements must be made?

Virty [35]

Answer:

You need to have the distance traveled and the time it took to travel that distance.

Explanation:

5 0

3 years ago

A weightlifter must exert 25 Newtons of force to

kakasveta [241]

$Work=Force \: × \: displacement \\ => W=Fs \\ \\ Given, \\ Force=25 \: N \\ Displacement=2m \\ \\ so \: work = 25 \: N \: \times 2m \\ = > work = 25kgm {s}^{ - 2} \times 2m \\ = > work = 50kg {m}^{2} {s}^{ - 2} \\ = > work = 50J$

This is the answer.

Hope it helps!!

6 0

3 years ago