<span>Since there is no friction, conservation of energy gives change in energy is zero
Change in energy = 0
Change in KE + Change in PE = 0
1/2 x m x (vf^2 - vi^2) + m x g x (hf-hi) = 0
1/2 x (vf^2 - vi^2) + g x (hf-hi) = 0
(vf^2 - vi^2) = 2 x g x (hi - hf)
Since it starts from rest vi = 0
Vf = squareroot of (2 x g x (hi - hf))
For h1, no hf
Vf = squareroot of (2 x g x (hi - hf))
Vf = squareroot of (2 x 9.81 x 30)
Vf = squareroot of 588.6
Vf = 24.26
For h2
Vf = squareroot of (2 x 9.81 x (30 – 12))
Vf = squareroot of (9.81 x 36)
Vf = squareroot of 353.16
Vf = 18.79
For h3
Vf = squareroot of (2 x 9.81 x (30 – 20))
Vf = squareroot of (20 x 9.81)
Vf = 18.79</span>
Answer: force, force
Explanation:
Newton’s third law states that there is an equal and opposite force
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Answer:
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The answer is Strontium(Sr)
Refraction is said to occur when there is a change in the speed of light.
<h3>What is the angle of refraction?</h3>
We know that refraction is said to occur when there is a change in the speed of light as it travels form one medium to another.
Given that the refractive index of the rectangular glass block is 1.5. The angle of refraction can be obtained by the use of the Snell's law;
n = sin i /sinr
n = refractive index
sini = angle of incidence
sin r = angle of refraction
sinr = sini/n
sinr = sin 45/1.5
= 0.471
r = 28 degrees
b) Now;
sinr =sin 45/1.2
sinr = 0.589
r = 36 degrees
For the glass
sinr = sin 36/1.5
sin r = 0.392
r = 23 degrees
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