Waves carry energy from one place to another. Because waves carry energy, some waves are used for communication, eg radio and television waves and mobile telephone signals. ... Some types of waves need to be transmitted through matter, either a solid, liquid or a gas. For example, water waves have to travel in water.
1) 
The capacitance of a parallel-plate capacitor is given by:

where
is the vacuum permittivity
A is the area of each plate
d is the distance between the plates
Here, the radius of each plate is

so the area is

While the separation between the plates is

So the capacitance is

And now we can find the energy stored,which is given by:

2) 0.71 J/m^3
The magnitude of the electric field is given by

and the energy density of the electric field is given by

and using
, we find

The answer is b.) the momentum before the collision is greater than the momentum after the collision
First, determine the mass of the object by dividing its weight on Earth by 9.8 m/s² as shown below,
m = 250 N / 9.8 m/s² = 25.51 kg
Then, multiply the obtained mass by the acceleration due to gravity (g) on Pluto.
W (in Pluto) = (25.51 kg) x (0.61 m/s²) = 15.56 N
Therefore, the object will only weigh 15.56 N.
Answer: Energy consumption and sustainability is important so that it remain available for future generation.
Explanation:
1. The home furnaces are likely to require fuel like coal, which will directly emit carbon dioxide and carbon monoxide gases. These should be replaced with the electrical furnaces. The old or more power consuming air conditioners should be replaced with new ones.
2. The water heaters should be tankless so their capacity to heat more water could be possible. The water heaters should be electricity saving.
3. Washer and dryers should be water savy and electricity savy. A front-loading washing machine is useful energy saver.
4. The LED lights are more electricity saving than conventional bulbs. Halogen lights are also electricity saving.