Answer:
a)
s
b) 3.41 mm
Explanation:
a)
We take the speed of light, c =
m/s and the refractive index of glass as 1.517.
Speed = distance/time
Time = distance/speed
Refractive index, n = speed of light in vacuum / speed of light in medium






b)
We take the refractive index of water as 1.333.
Speed in water = speed in vacuum / refractive index of water
Distance = speed * time



d = 3.41 mm
Answer:
A ruby is measures a 9 on the Mohs Scale of Hardness, second only to diamond and matched with sapphire. This makes a ruby an extremely hard and durable gemstone.
A sapphire is the birthstone for September. It is also a traditional gift for those celebrating 5th or 45th anniversaries.
It produces only virtual images is the answer
a. The speed of the pendulum when it reaches the bottom is 0.9 m/s.
b. The height reached by the pendulum is 0.038 m.
c. When the pendulum no longer swing at all, all the kinetic energy of the pendulum has been used to overcome frictional force.
<h3>Kinetic energy of the pendulum when it reaches bottom</h3>
K.E = 100%P.E - 18%P.E
where;
K.E(bottom) = 0.82P.E
K.E(bottom) = 0.82(mgh)
K.E(bottom) = 0.82(1 x 9.8 x 0.05) = 0.402 J
<h3>Speed of the pendulum</h3>
K.E = ¹/₂mv²
2K.E = mv²
v² = (2K.E)/m
v² = (2 x 0.402)/1
v² = 0.804
v = √0.804
v = 0.9 m/s
<h3>Final potential energy </h3>
P.E = 100%K.E - 7%K.E
P.E = 93%K.E
P.E = 0.93(0.402 J)
P.E = 0.374 J
<h3>Height reached by the pendulum</h3>
P.E = mgh
h = P.E/mg
h = (0.374)/(1 x 9.8)
h = 0.038 m
<h3>when the pendulum stops</h3>
When the pendulum no longer swing at all, all the kinetic energy of the pendulum has been used to overcome frictional force.
Thus, the speed of the pendulum when it reaches the bottom is 0.9 m/s.
The height reached by the pendulum is 0.038 m.
When the pendulum no longer swing at all, all the kinetic energy of the pendulum has been used to overcome frictional force.
Learn more about pendulum here: brainly.com/question/26449711
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