Answer:
Explanation: We have seasons because Earth's axis – the imaginary line that goes through the Earth and around which the Earth spins — is tilted. It's tilted about 23.5 degrees relative to our plane of orbit (the ecliptic) around the Sun. As we orbit our Sun, our axis always points to the same fixed location in space. Our northern axis points almost directly toward Polaris, the North Star.
Answer:
Some of the effects of a dam on the environment includes;
1) Increase in the amount of the greenhouse gases
2) Removal of the natural wetland and ocean carbon sinks
3) Disruption of the sources of nutrients in the ecosystem
4) Destruction of habitats
5) Raising of the sea levels and waste waters
6) Displace villages and communities
7) Dams have a potential to create flood risk
8) Dams lead to increased water loss due to evaporation and transpiration
9) Dams causes earthquakes
Explanation:
Dams are a source of renewable energy and are a means to prevent floods, however, dams can also have detrimental impact on the climate and the environment.
Answer:
Gravitational force
Explanation:
If two spheres have equal densities and they are subject only to their mutual gravitational attraction. We need to say that the quantities that must have the same magnitude for both spheres. So, the correct option is (E) i.e. gravitational force.
It is because of Newton's third law of motion. It states that the force due to object 1 to object 2 is same as force due to object 2 to object 1. The two forces act in opposite direction.
Hence, the correct option is (E) "Gravitational force".
Answer: 80J
Explanation:
According to the first principle of thermodynamics:
<em>"Energy is not created, nor destroyed, but it is conserved." </em>
Then this priciple (also called Law) relates the work and the transferred heat exchanged in a system through the internal energy 
, which is neither created nor destroyed, it is only transformed. So, in this especific case of the compressed gas:
(1)
Where:
is the variation in the internal (thermal) energy of the system (the value we want to find)
is the heat transferred out of the gas (that is why it is negative)
is the work is done on the gas (as the gas is compressed, the work done on the gas must be considered positive )
On the other hand, the work done on the gas is given by:
(2)
Where:
is the constant pressure of the gas
is the variation in volume of the gas
In this case the initial volume is 
and the final volume is 
.
This means:
(3)
Substituting (3) in (2):
(4)
(5)
Substituting (5) in (1):
(6)
Finally:
This is the change in thermal energy in the compression process.
My guesses would be g. or F
