With constant angular acceleration , the disk achieves an angular velocity at time according to
and angular displacement according to
a. So after 1.00 s, having rotated 21.0 rad, it must have undergone an acceleration of
b. Under constant acceleration, the average angular velocity is equivalent to
where and are the final and initial angular velocities, respectively. Then
c. After 1.00 s, the disk has instantaneous angular velocity
d. During the next 1.00 s, the disk will start moving with the angular velocity equal to the one found in part (c). Ignoring the 21.0 rad it had rotated in the first 1.00 s interval, the disk will rotate by angle according to
which would be equal to
My original answer was deleted because I added a link incase the photo wouldn't upload, but I guess I can retype it!
In this question I would look at the keypoints, such as "2 minutes with a constant speed of 4m/s."
What is found in this question is:
1- (S) speed = 4m/s (I will assume this means miles per second.
2- (T) time = two minutes.
When these things are read aloud with the following question, it will become known that in order to find the (D) distance, that you would/will need a formula(s).
In physics, there is a helpful formula known as the, "distance, speed and time equation."
An easy way to remember how to use this formula is through either drawing a triangle, and placing the lettering on how you would find the answer to which calculation you are trying to find.
Example of the triangle as best as I can provide:
(S) speed= (D) distance / (T) time. [S= D/T]
(T) time= (D) distance / (S) speed. [T= D/S]
(D) distance= (S) speed x (T) time. [D= (S)T]
Reflect on what you are looking for, which is the (D) distance the person would cover in 2 minutes at a constant speed of 4 m/s.
Fit the numbers into your equation.
D= (S)4 m/s x (T) 2 minutes
YOUR ANSWER:
(D) Distance = 0.298258 miles
I hoped this helped, and will help in future questions like these! Have a good day!
Answer:
180.04 nm
Explanation:
λ₀ = maximum wavelength for photoelectric emission in tungsten = 230 x 10⁻⁹ m
E₀ = maximum energy of ejected electron = 1.5 eV = 1.5 x 1.6 x 10⁻¹⁹ J
λ = wavelength of light used = ?
Using conservation of energy
Energy of the light used = Maximum energy required for photoelectric emission + Energy of ejected electron
λ = 180.04 x 10⁻⁹ m
λ = 180.04 nm
Answer: The correct answer is "The energy of the electrons emitted increases".
Explanation:
Photoelectric effect: It is the phenomenon in which the light of the particular frequency incidents on the surface of the metal then there is an emission of the electrons.
In this phenomenon, the saturation current increases with the increase in the intensity of the light.
The rate of flow of electrons constitutes the current. If the intensity of light increases then the rate of the electrons also increases.
In the given problem, When light is incident on a metal surface, it emits electrons. The rate of the electrons emitted increases.
Therefore, the correct option is (C).
Answer:
4.24m/s
Explanation:
Potential energy at the top= kinetic energy at the button
But kinetic energy= sum of linear and rotational kinetic energy of the hoop
PE= mgh
KE= 1/2 mv^2
RE= 1/2 I ω^2
Where
m= mass of the hoop
v= linear velocity
g= acceleration due to gravity
h= height
I= moment of inertia
ω= angular velocity of the hoop.
But
I = m r^2 for hoop and ω = v/r
giving
m g h = 1/2 m v^2 + 1/2 (m r^2) (v^2/r^2) = 1/2 m v^2 + 1/2 m v^2 = m v^2
and m's cancel
g h = v^2
Hence
v= √gh
v= √10×1.8
v= 4.24m/s