How heat transfer can cause fire to spread?

A fire can spread by radiation when the heat travels through electromagnetic waves in the air. When a fire breaks out, heat will travel in all directions until it reaches an object which will absorb it. When it reaches a combustible material, it will smoulder and eventually burn.

Part A - The apparent displacement of the mark is 4 cm.

The refractive index of a material, n = real depth, D/apparent depth, L.

So, n = D/L

Since the refractive index of the triangular glass prism is 1.5, n = 1.5. Also, the triangular glass prism is 12 cm thick and placed on a mark on a piece of paper resting on a horizontal bench. So, the real depth of the mark on the piece of paper through the triangular prism is D = 12 cm and its apparent depth is L.

Since n = D/L,

making L, subject of the formula, we have

L = D/n

Substituting the values of the variables into the equation, we have

L = D/n

L = 12 cm/1.5

L = 8 cm

so, the apparent depth of the mark is 8 cm.

So, the apparent displacement of the mark is d = D - L = 12 cm - 8 cm = 4 cm

Thus the apparent displacement of the mark is 4 cm.

Part B - The refractive index of water, n = 1.33.

The refractive index of a material, n = real depth, D/apparent depth, L.

So, n = D/L

Since the depth of water in the jar is 24 cm, the real depth, D = 24 cm.

Also, the bottom of the jar appears to be raised by 6 cm. So, the apparent depth, L = 24 cm - 6 cm = 18 cm

Since n = D/L, the refractive index of water n = D/L

Substituting the values of the variables into the equation, we have

n = D/L

= 24 cm/18 cm

= 1.33

So, the refractive index of water, n = 1.33.

Learn more about refractive index here: