Answer:
-10.8°, or 10.8° below the +x axis
Explanation:
The x component of the resultant vector is:
x = 3.14 cos(30.0°) + 2.71 cos(-60.0°)
x = 4.07
The y component of the resultant vector is:
y = 3.14 sin(30.0°) + 2.71 sin(-60.0°)
y = -0.777
Therefore, the angle between the resultant vector and the +x axis is:
θ = atan(y / x)
θ = atan(-0.777 / 4.07)
θ = -10.8°
The angle is -10.8°, or 10.8° below the +x axis.
The number of electrons emitted from the metal per second increases if the intensity of the incident light is increased.
Answer: Option B
<u>Explanation:</u>
As a result of photoelectric effect, electrons are emitted by the light incident on a metal surface. The emitted electrons count and its kinetic energy can measure as the function of light intensity and frequency. Like physicists, at the 20th century beginning, it should be expected that the light wave's energy (its intensity) will be transformed into the kinetic energy of emitted electrons.
In addition, the electrons count emitting from metal must vary with light wave frequency. This frequency relationship was expected because the electric field oscillates due to the light wave and the metal electrons react to different frequencies. In other words, the number of electrons emitted was expected to be frequency dependent and their kinetic energy should be dependent on the intensity (constant wavelength) of light.
Thus, the maximum in kinetic energy of electrons emitted increases with increase in light's frequency and is experimentally independent of light intensity. So, the number of emitted electrons is proportionate to the intensity of the incident light.
Answer:
1.56 J
Explanation:
The potential energy only depends on the vertical height from the ground level.
We consider the ground level to have zero P.E.
So when it is 2 m above the ground level,
P.E. = mgh
= 0.078×10×2
= 1.56 J
It is based on the idea that all the present continents were on supercontinent.
Answer:
A) Impulse is the same for both the objects
B) The higher is the speed, the greater will be the height.
Explanation:
Part a)
The time of interaction of the two bodies i.e the hanging mass and the stick is same. Thus, force caused by dart on the block = force caused by block on the dart. Hence, impulse is the same for both the objects.
Part B
The energy will be conserved in the entire reaction process
Hence, Kinetic energy = potential energy
0.5Mv^2 = gh(md+mb)
H is directly proportional to the square of speed.
Hence, the higher is the speed, the greater will be the height.
