Answer:
<h2>The answer is 67.5 km</h2>
Explanation:
The distance covered by an object given it's velocity and time taken can be found by using the formula
distance = velocity × time
From the question we have
distance = 90 × 0.75
We have the final answer as
<h3>67.5 km</h3>
Hope this helps you
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.
B) a rock being tossed high into the air
Answer:
I = 0.09[amp] or 90 [milliamps]
Explanation:
To solve this problem we must use ohm's law, which tells us that the voltage is equal to the product of the voltage by the current.
V = I*R
where:
V = voltage [V]
I = current [amp]
R = resistance [ohm]
Now, we replace the values of the first current into the equation
V = 180*10^-3 * R
V = 0.18*R (1)
Then we have that the resistance is doubled so we have this new equation:
V = I*(2R) (2)
The voltage remains constant therefore 1 and 2 are equals and we can obtain the current value.
V = V
0.18*R = I*2*R
I = 0.09[amp] or 90 [milliamps]
