Explanation

Explanation

To find the work function, we need to calculate the energy of the photon (E) and the kinetic energy of the electron (KE), then use the equation:

φ = E - KE

E = hc / λ = 1240 eV nm / 4000 nm = 3.1 eV

KE = (1/2)mv^2 ≈ (1/2) × 9.11 × 10^-31 kg × (6 × 10^5 m/s)^2 ≈ 1.64 × 10^-19 J ≈ 1.024 eV

φ = 3.1 eV - 1.024 eV ≈ 2.076 eV ≈ 2.1 eV

Explanation

The degrees of freedom refer to the number of independent ways a gas molecule can store energy.

For a monoatomic gas (e.g., noble gases like helium, neon, argon):

• It has only translational motion along the x, y, and z axes.
• There are no rotational or vibrational degrees of freedom.

Thus, the total degrees of freedom for a monoatomic gas is 3 (one for each spatial direction: x, y, and z).

Explanation

Given:

Initial efficiency (η₁) = 50% = 0.5

Initial cold body temperature (T₁) = 17°C = 290 K

Initial hot body temperature (T₂) = unknown

We know that the efficiency of a Carnot engine is:

η = 1 - (T₁ / T₂)

0.5 = 1 - (290 K / T₂)

T₂ = 580 K

Now, the hot body temperature is increased by 145°C:

New hot body temperature (T₂') = 580 K + 145°C = 725 K

New efficiency (η₂) is:

η₂ = 1 - (T₁ / T₂')

= 1 - (290 K / 725 K)

≈ 0.6

New efficiency (η₂) is approximately 60%.

Explanation

Explanation

Given:

Energy of photon (E) = 4.1 MeV

The total energy available for the electron and positron is:

E - 2 × 0.511 MeV = 4.1 MeV - 1.022 MeV = 3.078 MeV

Since the electron and positron share the energy equally, the kinetic energy of the electron is:

3.078 MeV / 2 = 1.539 MeV

Adding the rest mass energy of the electron (0.511 MeV), we get:

Energy of electron = 1.539 MeV + 0.511 MeV = 2.05 MeV

Explanation

Explanation

Explanation

Explanation