Answer: e. Christian Dopplerâ
Explanation:
Based on the information given, the scientist of the past that should definitely be included in the exhibit is Christian Dopplera.
He described how the frequency of sound waves and light is being affected by the relative speed of both the source and also the observer. This was referred to as the Doppler effect.
In this scenario, the Doppler effect can be used to show how the universe is expanding. Therefore, the correct option is E.
Missing graph. I attach it in the answer.
In a uniformly accelerated motion, the velocity at time t is given by:

where a is the acceleration and t is the time.
Given the previous equation, if we plot v(t) versus t, we find a straight line; moreover, a (the acceleration) represents the slope of the curve.
Looking at the graph, we see that when the time goes from 10 s to 20 s, the velocity increases from 4 m/s to 6 m/s. Therefore the slope of the curve is

and this corresponds to the acceleration.
So, the correct answer is <span>
0.2 m/s2.</span>
Answer: Strength of magnet and distance from magnetic material
Explanation:
The potential energy of a magnet is determined by the strength of the magnet and the distance between a magnet and another magnet or a magnetic material. Magnetic materials are materials that would be attracted when brought close to a magnet, example of magnetic materials are most metals.
I agree with the other comment