Answer:
Option C is the correct answer.
Explanation:
Considering vertical motion of ball:-
Initial velocity, u = 2 m/s
Acceleration , a = 9.81 m/s²
Displacement, s = 40 m
We have equation of motion s= ut + 0.5 at²
Substituting
s= ut + 0.5 at²
40 = 2 x t + 0.5 x 9.81 x t²
4.9t² + 2t - 40 = 0
t = 2.66 s or t = -3.06 s
So, time is 2.66 s.
Option C is the correct answer.
Answer: C
Reflection
Explanation: Light travels in a straight line. Reflection is one of the properties of light. And this is the property in which mirror make use of. The ability of light to bounce back. It's this bouncing back characteristics of light ray that eventually produce the image of an object by the mirror.
If the light ray is absorbed, no image will be produced.
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Answer:
i) Telescopes can be used to view far distant objects but the human eye can't view far distant objects.
ii) Telescopes uses two convex lenses producing a magnified image while the human eye only possesses one convex lens (image seen are smaller than that viewed under telescopes)
Explanation:
The telescopes can be used to view far distant objects due to their presence of two convex lenses. The two convex lenses are the objective lens (lens closer to object) and the eye piece lens (lens closer to eye). The object to be viewed forms an intermediate image first before the final image is seen using the eye piece lens.
The human eye only possess one convex lens and as such cannot view far ranged objects.