Answer:
Step-by-step explanation:
move the decimal so there is one non-zero digit to the left of the decimal point. the number of decimal places you move will be the exponent on the 10. if the decimal is being moved to the right, the exponent will be negative. if the decimal is being moved to the left, the exponent will be positive.
Answer:
a). 59.049°C
b). 2.1179 seconds
Step-by-step explanation:
Expression representing the final temperature after decrease in temperature of the metal from 100°C to T°C is,
T =
where x = duration of cooling
a). Temperature when x = 5 seconds
T = 100(0.9)⁵
= 59.049
≈ 59.049°C
b). If the temperature of the metal decreases from 100°C to 80°C
Which means for T = 80°C we have to calculate the duration of cooling 'x' seconds
80 =
0.8 =
By taking log on both the sides
log(0.8) =log[]
-0.09691 = x[log(0.9)]
-0.09691 = -0.045757x
x =
x = 2.1179
x ≈ 2.1179 seconds