<span><u>_Award brainliest if helped! </u>
B It’s a physical change because the water and the salt kept their original properties.</span>
Construct a vector diagram. It will be a right-angled triangle. One vector (the hypotenuse) represents the heading of the boat, one represents the current and one represents the resultant speed of the boat, which I'll call x. Their magnitudes are 20, 3 and x. Let the required angle = theta. We have:
<span>theta = arcsin(3/20) = approx. 8.63° </span>
<span>The boat should head against the current in a direction approx. 8.63° to the line connecting the dock with the point opposite, or approx. 81.37° to the shore line. </span>
<span>x = sqrt(20^2 - 3^2) </span>
<span>= sqrt(400 - 9) </span>
<span>= sqrt 391 </span>
<span>The boat's crossing time = </span>
<span>0.5 km/(sqrt 391 km/hr) </span>
<span>= (0.5/sqrt 391) hr </span>
<span>= approx. 0.025 hr </span>
<span>= approx. 91 seconds</span>
Answer:
A force
Explanation:
A push or a pull is an example of a force and can cause an object to speed up, slow down, etc.. Newton's laws tell us that 1- an object will not change its motion unless a force acts on it 2- the force on an object is equal to its mass times its acceleration. 3- The third law states that for every action (force) in nature there is an equal and opposite reaction.. However, forces like gravity and friction can resist movement.
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.
I think that this is false but I am not sure