Geothermal, Wind ,Solar, and Water turbine.
I hope I helped.
Answer:
a) 
b) 
c) 
d) 
would be the same.
would decrease.
would be the same.
Explanation:
a) On an inclined plane the force of gravity is the sine component of the weight of the block.
b) The friction force is equal to the normal force times coefficient of friction.
c) The work done by the normal force is zero, since there is no motion in the direction of the normal force.
d) The relation between the vertical height and the distance on the ramp is
According to this relation, the work done by the gravity wouldn't change, since the force of gravity includes a term of 
.
The work done by the friction force would decrease, because both the cosine term and the distance on the ramp would decline.
The work done by the normal force would still be zero.
Answer:
the wagon should be used as frame of reference if an observer said the child was not moving.
Explanation:
The state of motion of a body depends upon the frame of reference. It is the set of co-ordinates according to which the motion is analyzed. If a child is riding in a wagon, then he will be considered in motion to a person standing outside the wagon. Hence, if we take a frame of reference outside the wagon then the child must be in motion with respect to the observer. On the other hand if the observer is inside the wagon, then the child must be in rest with respect to the observer. Hence, if we take the wagon to be the frame of reference, then the child will be at rest with respect to the observer.
<u>Therefore, the wagon should be used as frame of reference if an observer said the child was not moving.</u>
Answer: Scientists found evidence of Earths magnetic field reversal in rocks on the ocean floor at plate boundaries. These rocks have alternating polarity due to magnetization that occurred during their cooling period. Using radio metric dating, scientist estimate that reversals occur approximately every several hundred thousand years.
Explanation:
