Given:
Mass of the rail road car, m = 2 kg
velocity of the three cars coupled system, v' = 1.20 m/s
velocity of first car,
= 3 m/s
Solution:
a) Momentum of a body of mass 'm' and velocity 'v' is given by:
p = mv
Now for the coupled system according to law of conservation of momentum, total momentum of a system before and after collision remain conserved:
(1)
where,
= velocity of the first car
= velocity of the 2 coupled cars after collision
Now, from eqn (1)


v' = 1.80 m/s
Therefore, the velocity of the combined car system after collision is 1.80 m/s
Explanation:
a) <em>Fixed points</em> are the temperatures at which a thermometer is calibrated. They can refer either to the actual temperatures used for calibration, or the thermometer readings at those temperatures.
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b) <em>Fundamental interval</em> is the difference between the fixed points. As with fixed points, it can refer either to the difference in actual temperature, or the difference in the corresponding thermometer readings.
Answer:
x = 45 cm
Explanation:
Given that,
The length of a rod, L = 50 cm
Mass, m₁ = 0.2 kg
It is at 40cm from the left end of the rod.
We need to find the distance from the left end of the rod should a 0.6kg mass be hung to balance the rod.
The centre of mass of the rod is at 25 cm.
Taking moments of both masses such that,

The distance from the left end is 40+5 = 45 cm.
Hence, at a distance of 45 cm from the left end it will balance the rod.
B. their distances from the sun.
Explanation:
Absolute Magnitude:
Astronomers defines the absolute magnitude of a stars brightness in terms of how bright a star appears from a standard distance of 10 parsecs. Parsec is a unit of distance in astronomy. 10 parsecs is equal to 32.6 light years.
Apparent Magnitude:
Apparent magnitude of a star refers to how bright the star appears at its distance from the Earth.
If two stars have the same absolute magnitude but their apparent magnitude differs, the reason is that the distance of both the stars from the Earth varies. Hence their brightness differs when measured from Earth. The farther a star is from the Earth, the fainter its brightness.
Keywords: star, brightness, parsec, light years, apparent magnitude, absolute magnitude
Learn more about stars and absolute magnitude from:
brainly.com/question/13002384
brainly.com/question/1384449
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Answer:
1.The Sun is located at one of the foci of the planets' elliptical orbits.
2.The path of the planets around the Sun is elliptical in shape.
Explanation:
As per Kepler's law of planet motion we know that all planets revolve around the sun in elliptical path in such a way that position of Sun must be at one of the focii of the path
So all planets are in elliptical path always
Position of sun is always at one of the focus
so correct answer will be
1.The Sun is located at one of the foci of the planets' elliptical orbits.
2.The path of the planets around the Sun is elliptical in shape.