All categories

3 years ago

How many feet does a No. 2 pencil last?

Physics

1 answer:

Ray Of Light [21]3 years ago

6 0

Answer:45,000

Explanation:

:TIL the average pencil holds enough graphite to draw a line about 35 miles long or to write roughly 45,000 words

You might be interested in

From a vantage point very close to the track at a stock car race, you hear the sound emitted by a moving car. You detect a frequ

Alexandra [31]

Approximately 15 m/s is the speed of the car.

<u>Explanation:</u>

<u>Given:</u>

speed of sound - 343 m/s

You detect a frequency that is 0.959 times as small as the frequency emitted by the car when it is stationary. So, it can be written as,

$f^{\prime}=0.959 f$

$\frac{f^{\prime}}{f}=0.959$

If there is relative movement between an observer and source, the frequency heard by an observer differs from the actual frequency of the source. This changed frequency is called the apparent frequency. This variation in frequency of sound wave due to motion is called the Doppler shift (Doppler effect). In general,

$f^{\prime}=\left(\frac{v+v_{0}}{v-v_{s}}\right) \times f$

Where,

$f^'$ - Observed frequency

f – Actual frequency

v – Velocity of sound waves

$v_0$ – Velocity of observer

$v_s$ - velocity of source

When source moves away from an observer at rest ( $v_{0} = 0$ ), the equation would be

$f^{\prime}=\left(\frac{v}{v-\left(-v_{s}\right)}\right) \times f$

$f^{\prime}=\left(\frac{v}{v+v_{s}}\right) \times f$

$\frac{f^{\prime}}{f}=\left(\frac{v}{v+v_{s}}\right)$

By substituting the known values, we get

$0.959=\left(\frac{343}{343+v_{s}}\right)$

$0.959\left(343+v_{s}\right)=343$

$0.959(343)+0.959\left(v_{s}\right)=343$

$328.937+0.959 v_{s}=343$

$0.959 v_{s}=343-328.937=14.063$

$v_{s}=\frac{14.063}{0.959}=14.66 \mathrm{m} / \mathrm{s}$

Approximately 15 m/s is the speed of the car.

3 0

3 years ago

A surface receiving sound is moved from its original position to a position three times farther away from the source of the soun

vazorg [7]

Answer:

c. nine times as low.

Explanation:

Sound intensity is defined as the acoustic power transferred by a sound wave per unit of normal area to the direction of propagation:

$I\propto \frac{1}{A}$

Since the sound wave has a spherical wavefront of radius r, then the area is given by:

$A=4\pi r^2$

Here r is the distance from the source of the sound. Thus sound intensity decreases as:

$I\propto \frac{1}{4\pi r^2}\\\\I'\propto \frac{1}{4\pi r'^2}\\\\I'\propto \frac{1}{4\pi (3r)^2}\\\\I'\propto \frac{1}{9} \frac{1}{4\pi r^2}\\\\I'\propto \frac{1}{9} I$

6 0

4 years ago

Can someone help my with my Physics lab pleaseeeee

den301095 [7]

Answer:

whats the question

Explanation:

where your question

4 0

3 years ago

Practicing good human relations skills and having a positive attitude will

skad [1K]

Have a positive effect on you as a human being. Your attitude will improve, your charisma will spread, and you will a better, more well rounded person.

7 0

4 years ago

Read 2 more answers

**100 POINTS**

lawyer [7]

Answer:

Explanation:

6 0

3 years ago