How does this happen?

The moon clearly exhibits a light and dark portion during most of the month except during full moon. What causes the dark portio

mylen [45]

While rotating around Earth the Moon also rotates around it's axis. These two rotations have almost same duration (27.3 and 27 days respectively). This is the reason why we always see the same side of Moon.

The dark part of a Moon is the part where there is night on the Moon, meaning there is no sunlight visible. This dark part depends on the Moon's position relative to Earth and Sun. The change in size is due to part of Moon-day. Dark part of Moon has night, bright part has day and the boundary has either sunrise or sunset.

8 0

3 years ago

A train travels 55 kilometers in 2 hours, and then 52 kilometers in 5 hours. What is its average speed?

bulgar [2K]

The formula for working out speed is distance ÷ time.

55 km ÷ 2 hours = 27.5 km/h (average speed for first part of journey)

52km ÷ 5 hours = 10.4 km/h (average speed for second part of journey)

(27.5 + 10.4) ÷ 2 = 18.95 km/h (average speed throughout the journey)

4 0

3 years ago

Read 2 more answers

What energy does black holes give off? A) photons B) dark matter C) dark energy D) none of the above

Umnica [9.8K]

never seen one although i guess the elegant answer is D) none of the mentioned posibilities

6 0

4 years ago

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A solid sphere and a solid cylinder , both uniform and having the same mass and radius, are released from rest at the same heigh

IRISSAK [1]

Answer:

I (cylinder) = 1/2 M R^2

I (sphere) = 2/5 M R^2

The equation of motion shows

I * alpha = M g R sin theta = const

An increase in the moment of inertia will result in a smaller acceleration

The cylinder will have the smallest forward velocity because it will arrive at the bottom after the sphere

5 0

3 years ago

Electrons are accelerated through a voltage difference of 230 kV inside a high voltage accelerator tube. What is the final kinet

Aliun [14]

Answer:

kinetic energy is 3.68 × $10^{-14}$ J

speed of these electrons is 0.5565 c

Explanation:

Given data

voltage difference = 230 kV

to find out

kinetic energy and speed of these electrons

solution

we know kinetic energy formula that is

kinetic energy = qv

kinetic energy = 1.6 × $10^{-19}$ × 230 × $10^{3}$

kinetic energy = 3.68 × $10^{-14}$ J

and

speed of electron that is

kinetic energy = m1c² - m2 c²

here m1 = m / √(1-v/c)²

so

KE/mc² = ( 1 / √(1-(v/c)² ) - 1

put value here

3.68 × $10^{-14}$ / (3× 10^8)²×9.11× $10^{-31}$ = ( 1 / √(1-v/c)² ) - 1

0.448835223 = ( 1 / √(1-(v/c)² ) - 1

( 1 / √(1-(v/c)² ) = 0.448835223 + 1 = 1.448835223

√(1-(v/c)² = 1 / 1.448835223 = 0.6902096

(v/c)² = 1 - 0.6902096 = 0.309790

v = 0.5565 c

speed of these electrons is 0.5565 c

5 0

3 years ago