Answer:
B object at rest
Explanation:
object at rest means it wouldn't be moving, like a parked car or sleeping person therefore, B is the correct answer
Answer:

Explanation:
According to the law of conservation of linear momentum, the total momentum of both pucks won't be changed regardless of their interaction if no external forces are acting on the system.
Being
and
the masses of pucks a and b respectively, the initial momentum of the system is

Since b is initially at rest

After the collision and being
and
the respective velocities, the total momentum is

Both momentums are equal, thus
Solving for 


The initial kinetic energy can be found as (provided puck b is at rest)


The final kinetic energy is


The change of kinetic energy is

Answer: B
Explanation: look at the chart, easy
From the case we know that:
- The moment of inertia Icm of the uniform flat disk witout the point mass is Icm = MR².
- The moment of inerta with respect to point P on the disk without the point mass is Ip = 3MR².
- The total moment of inertia (of the disk with the point mass with respect to point P) is I total = 5MR².
Please refer to the image below.
We know from the case, that:
m = 2M
r = R
m2 = 1/2M
distance between the center of mass to point P = p = R
Distance of the point mass to point P = d = 2R
We know that the moment of inertia for an uniform flat disk is 1/2mr². Then the moment of inertia for the uniform flat disk is:
Icm = 1/2mr²
Icm = 1/2(2M)(R²)
Icm = MR² ... (i)
Next, we will find the moment of inertia of the disk with respect to point P. We know that point P is positioned at the arc of the disk. Hence:
Ip = Icm + mp²
Ip = MR² + (2M)R²
Ip = 3MR² ... (ii)
Then, the total moment of inertia of the disk with the point mass is:
I total = Ip + I mass
I total = 3MR² + (1/2M)(2R)²
I total = 3MR² + 2MR²
I total = 5MR² ... (iii)
Learn more about Uniform Flat Disk here: brainly.com/question/14595971
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Answer: The energy from the sun passes through space in the form of invisible waves to the earth surface. It heats up the earth’s surface causing variation in climate.
Explanation:
The amount of incoming energy from the Sun decides the weather and climate of earth. If the energy that is incoming and outgoing on the earth, then climate is in equilibrium. The balance is depending on the scattering, absorption, reflection and transformation of energy.
The energy from sun passes through space and reaches the earth’s surface. On reaching surface, the solar energy warms the atmosphere releasing heat energy which gets transferred throughout the planets system by radiation, conduction and convection. Conduction happens in the atmosphere within first several millimeters close to the surface. This heated air expands as it is dense and rises causing transfer of heat to atmosphere through convection process. It results in formation of clouds.
The radiant energy from sun is transmitted via space in form of invisible waves. But much of the suns radiant energy, is transmitted back to atmosphere. The objects on earth like land, plants, animals absorb radiant energy as heat of which one third gets re-radiated back to atmosphere that is absorbed by carbon dioxide and water vapor. The atmosphere radiates heat energy back to earth increasing the earth temperature. This trapping of radiation is greenhouse effect.
The thermal energy obtained by convection currents are responsible for wind, cloud formation, and weather formation. The hydrosphere that comprises of 70% of earth’s surface absorbs solar energy.
On the basis of the above explanation is:
The energy from the sun passes through space in the form of invisible waves to the earth surface. It heats up the earth’s surface causing variation in climate.