If water in a tank is (W(t)=90-5t) litres, what type of change is it?
Answer and explanation
Correct answer: Linear decay
In W(t)=90-5t, the coefficient of t is -5. This means the amount of water decreases by 5 litres for every unit increase in time. Since the rate of decrease is constant, it is linear decay. A constant quantity has no t-term, while exponential decay has the variable in the exponent. Exam tip: In y=a+bt, b<0 indicates linear decay.
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What is the correct answer to this question?
Linear decay
Why is this the correct answer?
In W(t)=90-5t, the coefficient of t is -5. This means the amount of water decreases by 5 litres for every unit increase in time. Since the rate of decrease is constant, it is linear decay. A constant quantity has no t-term, while exponential decay has the variable in the exponent. Exam tip: In y=a+bt, b<0 indicates linear decay.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Linear growth and decay.
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