All categories

3 years ago

Why are there time zones? What is there purpose?

Physics

1 answer:

ExtremeBDS [4]3 years ago

8 0

Answer:

Timezones exist because of rotation and revolution

Explanation:

As Earth rotates on its axis, it moves about 15 degrees every 60 minutes. After 24 hours, it has completed a full rotation of 360 degrees. The scientists used this information to divide the planet into 24 sections or time zones. Each time zone is 15 degrees of longitude wide.

You might be interested in

z jaka maksymalna predkoscia porusza sie przez krotka chwile rowerzysta jezeli dysponuje moca maksymalna 420w i przy predkosci z

qwelly [4]

Answer:

12 m/s

Explanation:

English Translation

At what maximum speed is the cyclist traveling for a short time if he has a maximum power of 420W and at this speed he must overcome the resistance 35N.

The Power, P, expended by a moving body with velocity, v, moving against a resistive force of F is given as

P = Fv

P = 420 W

F = 35 N

v = ?

420 = 35v

v = (420/35) = 12 m/s

In Polish/Po polsku

Moc P, wydana przez poruszające się ciało z prędkością v, poruszająca się przeciw sile oporu F, jest podana jako

P = Fv

P = 420 W

F = 35 N

v = ?

420 = 35v

v = (420/35) = 12 m/s

Hope this Helps!!!

Mam nadzieję że to pomoże!!!

6 0

3 years ago

A 77.3 g mass is attached to a horizontal spring with a spring constant of 12.5 N/m and released from rest with an amplitude of

DENIUS [597]

Answer:

speed of the mass is 3.546106 m / s

Explanation:

given data

mass = 77.3 g = 77.3 × $10^{-3}$ kg

spring constant k = 12.5 N/m

amplitude A = 38.9 cm = 38.9 × $10^{-2}$ m

to find out

the speed of the mass

solution

we will apply here conservation energy that is

K.E + P.E = Total energy ..................1

so that Total energy = K.E max = P.E max

we know amplitude so we find out first P.E max that is

PE max = K.E + P.E

(1/2)kA² = (1/2)mv² + (1/2)kx²

kA^² = mv²+ kx²

so here v² will be

v² = k(A² - x²) / m

v = √[(k/m)×(A² - x²)] ............2

here x = (1/2)A so from from 2 equation

v = √[(k/m)×(A² - (A/2)²)]

v = √[(k/m)×(3/4×A²)]

now put all value

v = √[(12.5/ 77.3 × $10^{-3}$ )×(3/4×(38.9 × $10^{-2}$ )²)]

v = 3.546106 m / s

speed of the mass is 3.546106 m / s

6 0

3 years ago

Which is the force that results from use of a machine?

Goshia [24]

Answer:

D. Output force

Explanation:

The input force is the effort used to run the machine and this results in an output force.

3 0

2 years ago

A snowboarder starts from rest on an inclined planar snow surface and gives herself a tiny push to start sliding down the hill.

tiny-mole [99]

Answer:

v = 26.52 m/s

Explanation:

Here we know that as she passes the flag she will gain some speed

so here we can say that

Work done by all forces = change in kinetic energy of the system

so we will have

$W_g + W_f = \frac{1}{2}mv_f^2 - \frac{1}{2}mv_i^2$

here we know that

$W_g = mgh$

$W_f = -\mu mg d$

$v_i = 0$

h = 39.78 m

d = 27.81 m

so we have

$mgh - \mu mg d = \frac{1}{2}mv^2 - 0$

$(9.8)(39.78 - (0.14)(27.81)) = \frac{1}{2} v^2$

$v = 26.52 m/s$

8 0

3 years ago

A fisherman fishing from a pier observes that the float on his line bobs up and down, taking 2.4 s to move from its highest to i

mars1129 [50]

Answer:

(c) 10m/s

Explanation:

to find the speed of the waves you can use the following formula:

$v=\frac{\lambda}{T}$

λ: wavelength of the wave

T: period

the wavelength is the distance between crests = 48m

the period is the time of a complete oscillation of the wave. In this case you have that the float takes 2.4 s to go from its highest to the lowest point. The period will be twice that time:

T = 2(2.4s)=4.8s

by replacing you obtain:

$v=\frac{48m}{4.8s}=10\frac{m}{s}$

the answer is (c) 10m/s

4 0

3 years ago