Answer:

Given:
Radius of curvature (R) of a spherical mirror = 20
To Find:
Focal length (f)
Explanation:
Formula:

Substituting value of R in the equation:



Answer:
Explanation:
Given

Frictional Force is balanced by force due to car acceleration
Frictional force 




Answer:
θ=19.877⁰
Explanation:
Given data
Velocity Va=34.0 km/h
Velocity Va=100 km/h
To find
Angle θ
Solution
We want the bird to fly with velocity Vb=100 km/h with an angle θ relative to the ground so that the bird fly due south relative to the ground.From figure which is attached we got
Sinθ=(Va/Vb)
Sinθ=(34.0/100)
θ=Sin⁻¹(34.0/100)
θ=19.877⁰
We are given with
distance traveled through vacuum = 1.0 m
refractive index of water = 1.33
refractive index of glass = 1.50
refractive index of diamond = 2.42
distance traveled through water is = 1.0/1.33 = 0.75 m
distance traveled through water is = 1.0/1.50 = 0.67 m
distance traveled through water is = 1.0/2.42 = 0.41 m
To solve this problem we will use the definition of the period in a simple pendulum, which warns that it is dependent on its length and gravity as follows:

Here,
L = Length
g = Acceleration due to gravity
We can realize that
is a constant so it is proportional to the square root of its length over its gravity,

Since the body is in constant free fall, that is, a point where gravity tends to be zero:

The value of the period will tend to infinity. This indicates that the pendulum will no longer oscillate because both the pendulum and the point to which it is attached are in free fall.