The speed of the ball is always zero and the acceleration is always -g when it reaches the top of its motion. This is because when the ball is free, only gravity acts on it which is always downwards, hence g is the net acceleration and it is always negative. However the velocity does not direction change instantly, negative acceleration first slows down the ball with a positive velocity, until that point the ball keeps moving up, then the ball velocity becomes zero just before changing direction and becoming negative after which the ball will now go down along gravity. Hence the ball velocity is zero at the top (neither going up nor down). Mathematically this can be seen as velocity is the integration of acceleration.
Answer:
a) the values of the angle α is 45.5°
b) the required magnitude of the vertical force, F is 41 lb
Explanation:
Applying the free equilibrium equation along x-direction
from the diagram
we say
∑Fₓ = 0
Pcosα - 425cos30° = 0
525cosα - 368.06 = 0
cosα = 368.06/525
cosα = 0.701
α = cos⁻¹ (0.701)
α = 45.5°
Also Applying the force equation of motion along y-direction
∑Fₓ = ma
Psinα + F + 425sin30° - 600 = (600/32.2)(1.5)
525sin45.5° + F + 212.5 - 600 = 27.95
374.46 + F + 212.5 - 600 = 27.95
F - 13.04 = 27.95
F = 27.95 + 13.04
F = 40.99 ≈ 41 lb
Answer:
True, True, False, False, False, False.
Explanation:
The refraction index of a material is given by the formula n=c/v, where c is the speed of light in vacuum and v the speed of light in the material. If a ray of light crosses a boundary between two transparent materials and the medium the ray enters has a larger index of refraction it means that in this new medium the speed of light is smaller than on the other one, and then its wavelength is also reduced since f must remain the same (and
), otherwise there is a discontinuity on number of vibrations per second, which cannot happen. So we know that:
1) The wavelength of the light decreases as it enters into the medium with the greater index of refraction. True.
2) The frequency of the light remains constant as it transitions between materials. True.
3) The speed of the light remains constant as it transitions between materials. False.
4) The speed of the light increases as it enters the medium with the greater index of refraction. False.
5) The frequency of the light decreases as it enters into the medium with the greater index of refraction. False.
6) The wavelength of the light remains constant as it transitions between materials. False.
Answer:
The value is
Explanation:
From the question we are told that
The wavelength is 
The velocity is 
The mass of electron is 
Generally the energy of the incident light is mathematically represented as

Here c is the speed of light with value
h is the Planck constant with value 
So

=> 
Generally the kinetic energy is mathematically represented as

=> 
=> 
Generally the ionization energy is mathematically represented as

=>
Answer: Heat current through the insulator=196W
Electric power= 196W
Explanation: Given: Kglass = 0.040W/m
Temperature of inside glassTi=175°C
Temperature of outside glass To= 35°C
Area=1.4m^2 , L= 4×10^-2
Heat current(H)= K ×A× (Ti - To)/L
Substituting the values into the equation
H = 0.04 × K × 1.4 ×(175-35)/4×10^-2
H= 196W.
The electric power = Heat current =196W
The electric power is the magnitude of heat current