Answer:
U
Explanation:
The first law of thermodynamics states that:
where
U is the internal energy of the gas, which represents the sum of the chemical and thermal energy stored in the atoms and molecules of the gas
represents the variation of internal energy
Q is the heat absorbed by the system
W is the work done by the system
So, the sum of the chemical and thermal energy stored in atoms and molecules is represented by U, the internal energy.
Answer:
a) The speed of the electron as it reaches the inner conductor is closest to:
v = 1.45 × 10⁷m/s
b) The electric field magnitude between the cylinders is
E = 10,000V/m
Explanation:
given
inner radius of the cylinder r₁ = 20mm = 0.02m
outter radius of the cylinder r₂ = 80mm = 0.08m
potential difference V= 600V
mass of electron = 9.1×10⁻³¹kg
charge on electron = 1.6×10⁻¹⁹C
calculating the work done in bringing electron at inner conductor is
note:
∴W = (ΔV)q
(ΔV)q =
(600)1.6×10⁻¹⁹ = ¹/₂ × 9.1×10⁻³¹ × v²
v² ≈ 2.11 × 10¹⁴
v = 1.45 × 10⁷m/s
According to the energy conservation law, the total energy of an isolated system is always constant.
The energy of an isolated system can neither be created nor be destroyed, it can only convert one form to another form.
∴ the maximum electric field
E = ΔV/d
E = 600/d
where d is the distance between the two points
where d = 0.06m
E = 600/0.06
E = 10,000V/m
Note: the electric field due to the potential difference between to points depends upon the potential difference V and the distance between both points d.
Answer:
1280 mg
Explanation:
Radioactive decay is a phenomenon that occurs when a certain isotope of an element, said to be radioactive, decays, turning into a lighter nucleus and emitting radiation + energy in the process.
The radioactive decay of this isotope of polonium is described by the equation
where
is the amount of polonium left after time t
is the amount of polonium t time t = 0
is the half-life of the polonium, in days (it is the time it takes for the initial element to halve its amount)
IN this problem, we know that:
After t = 560 days, the amount of polonium left is . Therefore, we can re-arrange the equation, substituting t = 560 d, and solve for
to find the initial amount of polonium: