Answer:
* Larger mirrors collect more light and therefore fainter and more distant objects can have enough intensity to be detected
* arger mirrors decreases the angle of dispersion giving a better resolution of the bodies
Explanation:
Refracting telescopes get bigger every day for two main reasons.
* Larger mirrors collect more light and therefore fainter and more distant objects can have enough intensity to be detected
* the diffraction process for circular apertures is given by
θ = 1.22 λ / D
where d is the diameter of the mirror, therefore having larger mirrors decreases the angle of dispersion giving a better resolution of the bodies
Answer:
static coefficient = 0,203 & kinetic coefficient = 0,14
Explanation:
There are two (2) conditions, when the desk is about to move and when the desk is moving. In the attachements you can see the two free body diagram for each condition.
In the first condition, there is no movement and the force is 12 N, in the image we can see the total forces are equal to 0 and by the definition of the friction force we can get the static friction coefficient.
In the second condition there is movement in the direction of the force which is equal to 8 N, again by the definition of the friction force we can get the kinetic friction coefficient. Since the desk is moving with constant velocity there is not acceleration.
One with greater mass (8kg)
Answer:
ωB = 300 rad/s
ωC = 600 rad/s
Explanation:
The linear velocity of the belt is the same at pulley A as it is at pulley D.
vA = vD
ωA rA = ωD rD
ωD = (rA / rD) ωA
Pulley B has the same angular velocity as pulley D.
ωB = ωD
The linear velocity of the belt is the same at pulley B as it is at pulley C.
vB = vC
ωB rB = ωC rC
ωC = (rB / rC) ωB
Given:
ω₀A = 40 rad/s
αA = 20 rad/s²
t = 3 s
Find: ωA
ω = αt + ω₀
ωA = (20 rad/s²) (3 s) + 40 rad/s
ωA = 100 rad/s
ωD = (rA / rD) ωA = (75 mm / 25 mm) (100 rad/s) = 300 rad/s
ωB = ωD = 300 rad/s
ωC = (rB / rC) ωB = (100 mm / 50 mm) (300 rad/s) = 600 rad/s
Then the waves (and the energy they carry) are completely reflected from the surface of the impenetrable medium.
Example:
An ordinary mirror is a sheet of glass with a thin layer of aluminum
or silver stuck to the back of the glass. Light waves have no trouble
traveling through the glass, but they can't get through the silver layer
on the back of it. So the waves completely bounce off of the silver, and
go back through the glass in the direction they came from.
