Answer:
the answer should be the third statement
To measure the strength of an earthquake, you can use either a Richter scale or Mercalli scale. Richter scale uses the amplitued of the wave and the distance from the source. Mercalli scale uses observations of people and is not considered to be scientific as Richter scale.
Its good for a scientist to be skeptical because they dont willingly accept new ideas without thoroughly going over the research themselves and attempting to disprove a theory. skeptical scientists often reveal new information through doing their own examinations of a concept, which is why they are valuable scientists
<span>The charged balloon will stick to a neutral wall because of the Static Electricity:
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The matter is formed by atoms and these atoms are composed of electrons, protons and neutrons (the electrons have a negative charge, the protons have a positive charge and the neutrons have no charge).
As the balloon is charged (It gained electrons), and the charge of the same sign repel each other, when it approaches the wall, the electrons of this wall will move away, and the positive charges (protons) will remain in the nearest area to the balloon. As the charges of different signs are attracted, the balloon will be stuck to the wall.
Answer: The correct option is Option b.
Explanation:
Power is defined as the rate of work done by an object.
Mathematically,
.....(1)
And work done is the product of force exerted on the object times the displacement covered by that object.
Mathematically,

Putting this value in above equation, we get:

where,
P = power = ?W
F = Force exerted = 10N
s = Displacement = 400cm = 4m (Conversion factor: 1m = 100 cm)
t = Time taken = 8s
Putting values in above equation, we get

Hence, the correct option is Option b.