Answer:
Rate of change of area will be 
Explanation:
We have given rate of change of radius 
Radius of the circular plate r = 52 cm
Area is given by 
So 
Puting the value of r and 

So rate of change of area will be 
Answer:
8.89 m/s² west
Explanation:
Assume east is +x. Given:
v₀ = 120 m/s
v = 0 m/s
t = 13.5 s
Find: a
v = at + v₀
0 m/s = a (13.5 s) + 120 m/s
a = -8.89 m/s²
a = 8.89 m/s² west
We are given:
v0 = initial velocity = 18 km/h
d = distance = 4 km
v = final velocity = 75 km/h
a =?
<span>
We can solve this problem by using the formula:</span>
v^2 = v0^2 + 2 a d
75^2 = 18^2 + 2 (a) * 4
5625 = 324 + 8a
<span>a = 662.625 km/h^2</span>
Complete Question
The complete question is shown on the first uploaded image
Answer:
a

b
New 
Explanation:
From the question we are told that
The refractive index of the core is 
The refractive index of the cladding is 
Generally according to Snell's law

Where
is the largest angle a largest angle a ray will make with respect to the interface of the fiber and experience total internal reflection
![\theta_{max} = 90 - sin^{-1} [\frac{n_{cladding}}{n_{core}} ]](https://tex.z-dn.net/?f=%5Ctheta_%7Bmax%7D%20%3D%2090%20-%20sin%5E%7B-1%7D%20%5B%5Cfrac%7Bn_%7Bcladding%7D%7D%7Bn_%7Bcore%7D%7D%20%5D)
![\theta_{max} = 90 - sin^{-1} [\frac{1.421}{1.497}} ]](https://tex.z-dn.net/?f=%5Ctheta_%7Bmax%7D%20%3D%2090%20-%20sin%5E%7B-1%7D%20%5B%5Cfrac%7B1.421%7D%7B1.497%7D%7D%20%5D)

Given from the question the the largest angle is 5°
Generally the refraction index of the cladding is mathematically represented as


The formula is:
Work = Force · Displacement
F = m · g
F = 16 kg · 9.8 m/s² = 156.8 N
and we know that:
d = 0.8 m
W = 156.8 N · 0.8 m = 125.44 J
Answer:
W = 125.44 J.