Answer:
3.75 MeV
Explanation:
The energy of the photon can be given in terms of frequency as:
E = h * f
Where h = Planck's constant
The frequency of the photon is 6 * 10^20 Hz.
The energy (in Joules) is:
E = 6.63 x10^(-34) * 6 * 10^(20)
E = 39.78 * 10^(-14) J = 3.978 * 10^(-13) J
We are given that:
1 eV = 1.06 * 10^(-19) Joules
This means that 1 Joule will be:
1 J = 1 / (1.06 * 10^(-19)
1 J = 9.434 * 10^(18) eV
=> 3.978 * 10^(-13) J = 3.978 * 10^(-13) * 9.434 * 10^(18) = 3.75 * 10^(6) eV
This is the same as 3.75 MeV.
The correct answer is not in the options, but the closest to it is option C.
a . true hardness and density are physical properties
a = 3.09 m/s²
<h3>Explanation</h3>
This question doesn't tell anything about how long it took for the car to go through 105 meters. As a result, the <em>timeless </em>suvat equation is likely what you need for this question.
In the <em>timeless</em> suvat equation,
where
is the acceleration of the car;
is the <em>final</em> velocity of the car;
is the <em>initial</em> velocity of the car; and
is the displacement of the car.
Note that <em>v</em> and <em>u</em> are velocities. Make sure that you include their signs in the calculation.
In this question,
Apply the <em>timeless</em> suvat equation:
.
The value of is greater than zero, which is reasonable. Velocity of the car is negative, meaning that the car is moving backward. The car now moves to the back at a slower speed. Effectively it accelerates to the front. Its acceleration shall thus be positive.
In order to compute the final velocity of the trains, we may apply the principle of conservation of momentum which is:
initial momentum = final momentum
m₁v₁ = m₂v₂
The final mass of the trains will be:
10,000 + 10,000 = 20,000 kg
Substituting the values into the equation:
10,000 * 3 = 20,000 * v
v = 1.5 m/s
The final velocity of the trains will be 1.5 m/s
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