Please help this question.
1 answer:
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
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Answer:
The minimum number of hours that Sara could have worked is 31 hours .
The inequality representation of possible value of h is 105 + 7.25 h 329.75
Step-by-step explanation:
Given as :
The earning of Sara in per hour amount = $7.25 per hour
The additional earning of Sara as tips = $105
The Total earning of Sara = $329.75
Let The minimum number of hours that Sara could have worked = h hours
<u>Now, According to question</u>
The Total earning of Sara = The earning of Sara in per hour amount × minimum working hours + The additional earning of Sara as tips
I.e $329.75 = $7.25 per hour × h + $105
Or, $105 + $7.25 per hour × h = $329.75
Or, $7.25 per hour × h = $329.75 - $105
Or, 7.25 per hour × h = 224.75
∴ h =
I,e h = 31 hours
So, The number of hours Sara worked = h = 31 hours . Answer
Hence, The minimum number of hours that Sara could have worked is 31 hours .
The inequality representation of possible value of h is 105 + 7.25 h $329.75
Answer