Asmall metal bar, whose initial temperature was 10° c, is dropped into a large container of boiling water. how long will it take the bar to reach 70° c if it is known that its temperature increases 2° during the first second? (the boiling temperature for water is 100° c. round your answer to one decimal place.) sec how long will it take the bar to reach 98° c? (round your answer to one decimal place.)

Answer

According to newton law of cooling

and

now At Ta = 100

T₀ = 10 °C

T₁ = 12° C

10 = C + 100

C = -90

now,

at time equal to t

T(t) = 70

t = 48.88 s

hence, after 48.88 s the temperature of the body will be 70°C

b) time taken to reach 98°C

t = 390 s

hence, after 390 s the temperature of the body will be 98°C

don't know sorry bru

step-by-step explanation:

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls