When light travels from a medium with higher refractive index to a medium with lower refractive index, the critical angle is the angle of incidence above which light is reflected only (no refraction occurs), and the value of this critical angle is given by
where n2 is the refractive index of the second medium and n1 is the refractive index of the first medium.
In this problem, the first medium is the glass (
), while the second medium is oil (
), therefore the critical angle is given by
Answer
Radius of the wheel r = 2.1 m
Moment of inertia I = 2500 Kg m²
Tangential force applied F = 18 N
Time interval t = 16 s
Initial angular speed ω1 = 0
Final angular speed ω2 = ?
Let α be the angular acceleration.
Torque applied τ = Iα
F r = Iα
Angular acceleration α = F r/I
= 
= 0.015 rad/s²
(a)From rotational kinematic relation
Final angular speed ω₂ = ω₁ + αt
= 0 + (0.015 rad/s^2 * 16 s)
= 0.24 rad/s
(b) Work done W = 0.5 Iω₂² - (1/2)Iω₁²
= 0.5*( 2500 Kg m²)(0.24 rad/s)^2 - 0
= 72 J
(c) Average power supplied by the child P = W/t = 
= 4.5 watt
Answer:
0.4455 m
Explanation:
g = Acceleration due to gravity = 9.81 m/s²
Total mass is
Here the spring constant is not given so let us assume it as 
Here, the forces are balanced
The springs are compressed by 0.4455 m
Answer:
R = 0.1 ohms
Explanation:
It is given that,
Voltage of the battery, V = 12.5 V
Current flowing in the car's starter, I = 125 A
We need to find the effective resistance of a car's starter. It can be calculated using Ohm's law. Let R is the resistance.
So, the resistance of the car's starter is 0.1 ohms.
