The primary source would be the original article published in a scientific journal. All other choices would be based on information from the original article.
Newspapers would only pick up the information from the journal itself, or from the authors. Books follow after the original article, after it has gained momentum among the research community. The public lecture at a museum would be based on work from the journal article.
Answer:

Explanation:
Acceleration is defined as the change in velocity divided by the time it took to produce such change. The formula then reads:

Where Vf is the final velocity of the object, (in our case 80 m/s)
Vi is the initial velocity of the object (in our case 0 m/s because the object was at rest)
and t is the time it took to change from the Vi to the Vf (in our case 0.05 seconds.
Therefore we have:

Notice that the units of acceleration in the SI system are
(meters divided square seconds)
I believe the answer is c
Answer:
Revise energy transfers and use sankey diagrams to calculate the efficiency of these conversions with BBC ... Efficiency is a measure of how much useful energy is converted. Part of ... This is the Sankey diagram for a typical filament lamp: 100 joules of electrical energy is converted to 10 joules of light energy and 90 joules.
Explanation: