Answer:
θ₄ = 37.2º
Explanation:
For this exercise it must be solved in two parts, the first part we look for the critical angle, for this we use the law of refraction with the angle in the middle of transmission of tea = 90º
n₁ sin θ₁= n₂ sin 90
θ₁ = sin⁻¹
θ₁ = sin⁻¹ (1.33 / 1.43)
θ₁ = 68.4º
They indicate that the angle of incidence is half of the critical angle
θ₃ = 68.4 / 2 = 34.2º
Let's use the law of refraction again
n₁ sin θ₃ = n₂ sin θ₄
sin θ₄ = sin θ₃
sin θ₄ = sin 34.2
θ₄ = sin⁻¹ 0.604345
θ₄ = 37.2º
A is the correct answer.
The less the mass of something, the faster the kinetic energy.
Hope this helps :)
Answer:
The elastic potential energy is zero.
The net force acting on the spring is zero.
Explanation:
The equilibrium position of a spring is the position that the spring has when its neither compressed nor stretched - it is also called natural length of the spring.
Let's now analyze the different statements:
The spring constant is zero. --> false. The spring constant is never zero.
The elastic potential energy is at a maximum --> false. The elastic potential energy of a spring is given by
where k is the spring constant and x the displacement. Therefore, the elastic potential energy is maximum when x, the displacement, is maximum.
The elastic potential energy is zero. --> true. As we saw from the equation above, the elastic potential energy is zero when the displacement is zero (at the equilibrium position).
The displacement of the spring is at a maxi
num --> false, for what we said above
The net force acting on the spring is zero. --> true, as the spring is neither compressed nor stretched
Answer:
C) they all have the same angular speed
D) they all have the same angular acceleration
Explanation:
Wrong --> they all have the same tangential speed. The points close to the axis will have less speed than the points away from the axis.
Wrong --> they all have the same tangential acceleration. Similarly, the points close to the axis will have smaller acceleration than the points away from the axis.
Correct --> they all have the same angular speed. Angular speed is the same for all the particles in the rotating object.
Correct --> they all have the same angular acceleration. Angular acceleration is the same for all the particles in the rotating object.
This all comes from the following relations:
v = ωR
a = αR
where ω is the angular velocity and α is the angular acceleration.
As can be seen from above, tangential velocity and acceleration depends on the distance from the axis, whereas the angular velocity and acceleration is the same for all the points on the rotating body.