Ask question

Ask question

All categories

3 years ago

7

A general rule for estimating the distance in kilometers between an observer and a lightning bolt is to count the number of seco

nds between seeing the lightning and hearing it, and dividing by
a) 5
b) 3
c) 2
d) 4
e) none of these

1 answer:

Svetlanka [38]3 years ago

4 0

Answer:

option b ) is correct

Explanation:

Let d be the distance in km from the place of lightning . velocity of sound is 340 m /s approx

in km/ s it is 0.34 km/s

time in sec taken by sound to cover a distance of d km

d / .34 = t

d = .34 t

d = $\frac{t}{\frac{1}{0.34} }$

d = t / 3

so option b ) is correct . ,

You might be interested in

A race car has a centripetal acceleration of 15.625 m/s2 as it goes around a curve. If the curve is a circle with radius 40 m, w

myrzilka [38]

The centripetal acceleration is given by
$a_c = \frac{v^2}{r}$
where v is the tangential speed and r the radius of the circular orbit.

For the car in this problem, $a_c = 15.625 m/s^2$ and r=40 m, so we can re-arrange the previous equation to find the velocity of the car:
$v= \sqrt{a_c r}= \sqrt{(15.625 m/s^2)(40 m)}=25 m/s$

8 0

3 years ago

A ship maneuvers to within 2.46×10³ m of an island’s 1.80 × 10³ m high mountain peak and fires a projectile at an enemy ship 6.1

Nesterboy [21]

Answer:

The distance close to the peak is 597.4 m.

Explanation:

Given that,

Distance of the first ship from the mountain $d=2.46\times10^{3}\ m$

Height of island $h=1.80\times10^{3}\ m$

Distance of the enemy ship from the mountain $d'=6.10\times10^{2}\ m$

Initial velocity $v=2.55\times10^{2}\ m/s$

Angle = 74.9°

We need to calculate the horizontal component of initial velocity

Using formula of horizontal component

$v_{x}=v\cos\theta$

Put the value into the formula

$v_{x}=2.55\times10^{2}\cos74.9$

$v_{x}=66.42\ m/s$

We need to calculate the vertical component of initial velocity

Using formula of vertical component

$v_{y}=v\sin\theta$

Put the value into the formula

$v_{y}=2.55\times10^{2}\sin74.9$

$v_{y}=246.19\ m/s$

We need to calculate the time

Using formula of time

$t=\dfrac{d}{v_{x}}$

$t=\dfrac{2.46\times10^{3}}{66.42}$

$t=37.03\ sec$

We need to calculate the height of the shell on reaching the mountain

Using equation of motion

$H= v_{y}t-\dfrac{1}{2}gt^2$

Put the value in the equation

$H=246.19\times37.03-\dfrac{1}{2}\times9.8\times(37.03)^2$

$H=2397.4\ m$

We need to calculate the distance close to the peak

Using formula of distance

$H'=H-h$

Put the value into the formula

$H'=2397.4-1800$

$H'=597.4\ m$

Hence, The distance close to the peak is 597.4 m.

6 0

3 years ago

Which best describes the electromagnetic force?

Solnce55 [7]

B.strong but weaker than the weak force

7 0

3 years ago

Read 2 more answers

If the pH of a solution decrease's, is the solution getting more acidic or lees acidic

enyata [817]

Answer:

The solution becomes more acidic.

Explanation:

As the pH of a solution decreases, the concentration of hydrogen ions [H+] increases. Acidic solutions have a higher concentration of hydrogen ions and a lower pH.

I hope this helped. :)

6 0

3 years ago

Planet X has no atmosphere. This planet will most likely _____.

eduard

A) be too hot to support life

5 0

3 years ago

Read 3 more answers