The correct answer is 1 and 4.
Burning of fossil fuels releases harmful gases to the atmosphere which leads to climate change. Burning of hydrogen gas releases water which has no negative effect on climate.
Burning of both fossil fuels and hydrogen takes place inside expensive fuel cells.
Fossil fuels are widely available and easy to locate whereas hydrogen is available in the combined form with other elements. Hydrogen are not found in pure form on earth.
Fossil fuels are non-renewable source of energy which means they cannot be replaced in short time.
Answer:
a
The radial acceleration is 
b
The horizontal Tension is 
The vertical Tension is 
Explanation:
The diagram illustrating this is shown on the first uploaded
From the question we are told that
The length of the string is 
The mass of the bob is 
The angle made by the string is 
The centripetal force acting on the bob is mathematically represented as

Now From the diagram we see that this force is equivalent to
where T is the tension on the rope and v is the linear velocity
So

Now the downward normal force acting on the bob is mathematically represented as

So

=> 
=> 
The centripetal acceleration which the same as the radial acceleration of the bob is mathematically represented as

=> 
substituting values


The horizontal component is mathematically represented as

substituting value

The vertical component of tension is

substituting value

The vector representation of the T in term is of the tension on the horizontal and the tension on the vertical is

substituting value
![T = [(0.3294) i + (3.3712)j ] \ N](https://tex.z-dn.net/?f=T%20%20%3D%20%5B%280.3294%29%20i%20%20%2B%20%283.3712%29j%20%5D%20%5C%20%20N)
Depends on what the area is. If it’s a rural place, Wood is cheep & easy to build. If there’s a lot of corrosion, strong weather/hurricane, bricks.
Hi!
Condensation is crucial to the water cycle because it is responsible for the formation of clouds. These clouds may produce precipitation, which is the primary route for water to return to the Earth's surface within the water cycle. Condensation is the opposite of evaporation.
Hope this helps!
~CoCo