Answer:
4. It is the force of the road on the tires (an external force) that stops the car.
Explanation:
If there is no friction between the road and the tires, the car won't stop.
You can see this, for example, when there is ice on the road. You can still apply the brakes (internal force), but since there is no friction (external force) the car won't stop.
The force of the brakes on the wheels is not what makes the car stop, it is the friction of the road against still tires that makes it stop.
The moment of inertia is the rotational analog of mass, and it is given by
the product of mass and the square of the distance from the axis.
- The moment of inertia changes as the position of the weight is changed, which indicates that; statement is incorrect
Reasons:
The weight on each arm that have adjustable positions can be considered as point masses.
The moment of inertia of a point mass is <em>I</em> = m·r²
Where;
m = The mass of the weight
r = The distance (position) from the center to which the weight is adjusted
Therefore;
The moment of inertia, <em>I </em>∝ r²
Which gives;
Doubling the distance from the center of rotation, increases the moment of inertia by factor of 4.
Therefore, the statement contradicts the relationship between the radius of rotation and moment of inertia.
Learn more about moment of inertia here:
brainly.com/question/4454769
D: Sóng có thể truyền qua khoảng không của không gian,
với tốc độ ánh sáng.
Answer:
y = 80.2 mille
Explanation:
The minimum size of an object that can be seen is determined by the diffraction phenomenon, if we use the Rayleigh criterion that establishes that two objects can be distinguished without the maximum diffraction of a body coincides with the minimum of the other body, therefore so much for the pupil of the eye that it is a circular opening
θ = 1.22 λ/ d
in a normal eye the diameter of the pupils of d = 2 mm = 0.002 m, suppose the wavelength of maximum sensitivity of the eye λ = 550 nm = 550 10⁻⁹ m
θ = 1.22 550 10⁻⁹ / 0.002
θ = 3.355 10⁻⁴ rad
Let's use trigonometry to find the distance supported by this angle, the distance from the moon to the Earth is L = 238900 mille = 2.38900 10⁵ mi
tan θ = y / L
y = L tan θ
y = 2,389 10⁵ tan 3,355 10⁻⁴
y = 8.02 10¹ mi
y = 80.2 mille
This is the smallest size of an object seen directly by the eye
The answer to this is aluminum foil.