Answer:
A. 1.64 J
Explanation:
First of all, we need to find how many moles correspond to 1.4 mg of mercury. We have:
where
n is the number of moles
m = 1.4 mg = 0.0014 g is the mass of mercury
Mm = 200.6 g/mol is the molar mass of mercury
Substituting, we find
Now we have to find the number of atoms contained in this sample of mercury, which is given by:
where
n is the number of moles
is the Avogadro number
Substituting,
atoms
The energy emitted by each atom (the energy of one photon) is
where
h is the Planck constant
c is the speed of light
is the wavelength
Substituting,
And so, the total energy emitted by the sample is
Answer:
(a) 3.807 s
(b) 145.581 m
Explanation:
Let Δt = t2 - t1 be the time it takes from the moment when the motorcycle starts to accelerate until it catches up with the car. We know that before the acceleration, both vehicles are travelling at a constant speed. So they would maintain a distance of 58 m prior to the acceleration.
The distance traveled by car after Δt (seconds) at 
speed is
The distance traveled by the motorcycle after Δt (seconds) at 
speed and acceleration of a = 8 m/s2 is
We know that the motorcycle catches up to the car after Δt, so it must have covered the distance that the car travels, plus their initial distance:
(b)
The work-energy theorem states that the change in kinetic energy of the particle is equal to the work done on the particle:
The work done on the particle is the integral of the force on dx:
So, this corresponds to the change in kinetic energy of the particle.
Answer:
it's ii) R is correct while A is incorrect
Explanation:
cuz, both statements are correct but the reason is not the correct reason for the assertion,
Answer:
1.69 T
Explanation:
Applying,
F = BvqsinФ.................. Equation 1
Where F = Force, B = magnetic field, v = velocity, q = charge on an electron, Ф = angle between the electron and the field.
make B the subject of the equation,
B = F/(vqsinФ)............. Equation 2
From the question,
Given: F = 2.0×10⁻¹³ N, v = 7.4×10⁵ m/s, Ф = 90°
Constant: q = 1.60×10⁻¹⁹ C
Substitute into equation 2
B = 2.0×10⁻¹³/(7.4×10⁵×1.60×10⁻¹⁹×sin90°)
B = 0.169×10
B = 1.69 T
