First question: 800J
Second question: 20.4m
Light having a dual nature and acting like both a wave and a particle is the correct statement in this scenario.
<h3>What is Light?</h3>
This refers to the electromagnetic radiation found in the electromagnetic spectrum that is perceived by the human eye and has a dual nature. It doesn't require a medium for its propagation unlike sound.
The dual nature of light is as a result of it behaving like a photon which is why it travels in straight lines.
It also behave like a wave because it undergoes processes such as reflection, refraction etc which are common to waves.
Read more about Light here brainly.com/question/1363382
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Answer:
50 watts
Explanation:
Applying,
Power (P) = Workdone (W)/Time(t)
But,
Work done (W) = Force (F)×distance(d)
Therefore,
P = Fd/t..................... Equation 1
Where P = power of the weightlifter, F = Force applied, d = distance, t = time.
From the question,
Given: F = 200 N, d = 0.5 m, t = 2 s
Substitute these values into equation 1
P = (200×0.5)/2
P = 100/2
P = 50 watts
Mechanical advantage of a machine is the ratio of the output force over the input force or M=Fo/Fi. Since M=1, Fi=Fo, or the input force is equal to the output force. This means that to raise the refrigerator that weighs 900 N, we need the same input force of 900 N, or Fo=Fi=900 N.