a) One similarity between heat and temperature is that both are related to the internal energy of a…

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a) One similarity between heat and temperature is that both are related to the internal energy of a substance.

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5.

a) One similarity between heat and temperature is that both are related to the internal energy of a substance.

b) The linear expansivity of metal Y ( $\alpha_Y = 1.82 \times 10^{-5} \text{ K}^{-1}$ ) is greater than that of metal X ( $\alpha_X = 1.51 \times 10^{-5} \text{ K}^{-1}$ ). When heated, metal Y expands more than metal X. Therefore, the bimetallic strip will bend towards metal X (the metal with lower expansivity).

\text{Diagram of bimetallic strip after heating:}

(The strip bends with X on the inside of the curve and Y on the outside.)

6.

i) Let $L_P, L_Q, L_R$ be the lengths of strings P, Q, and R respectively.
Given: $L_P = 2 L_Q$
Given: $L_R = \frac{1}{3} L_Q$
From the first equation, $L_Q = \frac{1}{2} L_P$ .
Substitute this into the second equation:

L_R = \frac{1}{3} \left(\frac{1}{2} L_P\right)

L_R = \frac{1}{6} L_P

The relationship between P and R is $\boxed{L_P = 6 L_R}$ .

ii) The string that will produce a note of the highest pitch when plucked is R.

iii) The reason is that the frequency of a vibrating string is inversely proportional to its length (for equal tension). String R is the shortest ( $L_R = \frac{1}{3} L_Q$ ), so it will vibrate at the highest frequency, producing the highest pitch.

7.
To determine the angle of refraction, we use Snell's Law:

\frac{\sin i}{\sin r} = \frac{v_1}{v_2}

Substitute the given values into the formula.
$\frac{\sin 60^\circ}{\sin r} = \frac{3.0 \times 10^8 \text{ ms}^{-1}}{2.0 \times 10^8 \text{ ms}^{-1}}$ $\frac{\sin 60^\circ}{\sin r} = 1.5$
Solve for $\sin r$ .
$\sin r = \frac{\sin 60^\circ}{1.5} = \frac{0.8660}{1.5}$ $\sin r \approx 0.5773$
Calculate the angle of refraction, $r$ .
$r = \arcsin(0.5773)$ $r \approx \boxed{35.26^\circ}$
8.

a) Two uses of electromagnets are:
- In electric bells
- In lifting heavy iron objects (e.g., in scrap yards)
b) The soft iron bar can be converted to a magnet by the stroking method. Stroke the soft iron bar repeatedly in the same direction with one pole of the bar magnet. This aligns the magnetic domains within the soft iron, magnetizing it.

9.

a) Reactance is the opposition to the flow of alternating current (AC) in a circuit due to the presence of capacitance or inductance. It is measured in ohms ( $\Omega$ ).

b) To calculate the frequency, we use the formula for capacitive reactance:
$X_C = \frac{1}{2 \pi f C}$
Rearrange the formula to solve for frequency, $f$ .
$f = \frac{1}{2 \pi X_C C}$
Substitute the given values ( $C = 5 \text{ µF} = 5 \times 10^{-6} \text{ F}$ , $X_C = 3000 \text{ Ω}$ , $\pi = 3.14$ ).
$f = \frac{1}{2 \times 3.14 \times 3000 \text{ Ω} \times 5 \times 10^{-6} \text{ F}}$
Calculate the frequency.
$f = \frac{1}{0.0942}$ $f \approx \boxed{10.62 \text{ Hz}}$
10.

a) Photo-electrons are electrons emitted from the surface of a material (typically a metal) when light of a sufficiently high frequency shines on it, a phenomenon known as the photoelectric effect.

b) To calculate the threshold frequency, we first convert the work function to Joules.
Convert the work function ( $\phi$ ) from electron volts (eV) to Joules (J).
$\phi = 3.5 \text{ eV} \times (1.6 \times 10^{-19} \text{ J/eV})$ $\phi = 5.6 \times 10^{-19} \text{ J}$
Use the formula relating work function and threshold frequency ( $f_0$ ).
$\phi = h f_0$
Solve for $f_0$ and substitute Planck's constant ( $h = 6.6 \times 10^{-34} \text{ Js}$ ).
$f_0 = \frac{\phi}{h} = \frac{5.6 \times 10^{-19} \text{ J}}{6.6 \times 10^{-34} \text{ Js}}$ $f_0 \approx \boxed{8.48 \times 10^{14} \text{ Hz}}$
11.

a) Two health hazards of X-rays are:
- Cell damage and increased risk of cancer.
- Genetic mutations in reproductive cells.
b) The distinction between soft and hard X-rays is primarily based on their energy and penetrating power:
- Soft X-rays have lower energy, longer wavelengths, and are less penetrating.
- Hard X-rays have higher energy, shorter wavelengths, and are more penetrating.

A) One similarity between heat and temperature is that both are related to the internal energy of a substance.

Step-by-step solution

Substitute the given values into the formula.

Solve for $\sin r$ .

Calculate the angle of refraction, $r$ .

Rearrange the formula to solve for frequency, $f$ .

Substitute the given values ( $C = 5 \text{ µF} = 5 \times 10^{-6} \text{ F}$ , $X_C = 3000 \text{ Ω}$ , $\pi = 3.14$ ).

Calculate the frequency.

Convert the work function ( $\phi$ ) from electron volts (eV) to Joules (J).

Use the formula relating work function and threshold frequency ( $f_0$ ).

Solve for $f_0$ and substitute Planck's constant ( $h = 6.6 \times 10^{-34} \text{ Js}$ ).

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More Physics Questions

A) One similarity between heat and temperature is that both are related to the internal energy of a substance.

Step-by-step solution

Substitute the given values into the formula.

Solve for sin⁡r\sin rsinr.

Calculate the angle of refraction, rrr.

Rearrange the formula to solve for frequency, fff.

Substitute the given values (C=5 µF=5×10−6 FC = 5 \text{ µF} = 5 \times 10^{-6} \text{ F}C=5 µF=5×10−6 F, XC=3000 ΩX_C = 3000 \text{ Ω}XC​=3000 Ω, π=3.14\pi = 3.14π=3.14).