The correct answer to the question is : 1) Converting energy and 2) Within about twenty years, natural gas forms.
EXPLANATION:
In coal fired power plants, the water is heated by burning coals. The heat produced in this process will convert water into steam. The steam is allowed to rotate the turbine. The turbine is attached to a generator which converts the kinetic energy of the steam into electric energy due to electromagnetic induction.
Hence, turbine helps in converting energy.
As per the second question, Walt listed the steps that occur during the formation of natural gas.
The natural gas is produced due to natural phenomenon. For this, millions of years are passed. So, it is a long range process in which the fossil of animals and planets buried beneath the surface are converted into natural gas under high pressure.
Hence, the mistake of Walt is that the natural gas is produced withing twenty years.
S ?
U 0m/s
V ?
A 0.1m/s^2
T 2min (120 sec)
S=ut+0.5at^2
S=0(120 sec)+0.5(0.1m/s^2)(120 sec)^2
S=720m
Distance double 720m*2=1440m
V^2=u^2+2as
V^2=(0)^2+2(0.1 m/s^2)(1440m)
V^2=288
V= square root of 288=12 root 2=16.97 to 2 decimal places
You know that when the displacement is equal to the amplitude (A), the velocity is zero, which implies that the kinetic energy (KE) is zeero, so the total mechanical energy (ME) is the potential energy (PE).
And you know that the potential energy, PE, is [ 1/2 ] k (x^2)
Then, use x = A, to calculate the PE in the point where ME = PE.
ME = PE = [1/2] k (A)^2.
At half of the amplitude, x = A/2 => PE = [ 1/2] k (A/2)^2
=> PE = [1/4] { [1/2]k(A)^2 } = .[1/4] ME
So, if PE is 1/4 of ME, KE is 3/4 of ME.
And the answer is 3/4
