A man takes a brick out of the fire when it's at 285 degree Celsius, he drops it in a bucket of water. then covers the bucket. the bucket and cover are made of an insulating material. the bucket contains 2.6 kg of ice originally at -5 degree celsius. the 1.3 kg brick is made of iron .which has a specific heat of 448J/kg degree celsius. lets find out the temperature of brick and water once equilibrium is reached. specific heats of ice , liquid water, steam are 2090,4186,1970 respectively

The equilibrium temperature of brick and water is 2.82 Kelvin

Explanation:

Initial Temperature Ø of the brick = 285 degree Celsius

Initial temperature of ice = - 5 degree Celsius

Mass of iron = 1.3kg

Specific heat capacity c of iron = 448J/kg

In thermal experiments,

Heat lost = heat gain.

Let's first calculate the heat lost

The brick will loose heat.

H =mcØ

Heat lost = 1.3 × 448 × (285 - T)

Heat lost = 582.4( 285 - T )

Now let's calculate for heat gain

Heat gain = mcØ + mcØ + mcØ

Heat gain = [(2.6×2090) + (2.6×4186) + (2.6×1970)](T - -5)

Heat gain = 5434 + 10883.6 + 5122(T+5)

Heat gain = 21439.6( T + 5)

Equating the heat lost and the heat gain leads to

582.4( 285 - T) = 21439.6(T+5)

Open both bracket

165984 - 582.4T = 21439.6T + 107198

Collect the like terms

21439.6T - 582.4T = 165984 - 107198

20857.2T = 58786

T = 58786/20857.2

T = 2.82 Kelvins

The equilibrium temperature of brick and water is 2.82 Kelvin

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

the part of the wave he is travelling on is the crest