Consider the following problem:The number of people remaining in the auditorium is decreasing at a rate of r(t)=−0.1t people per minute (where t is the time in minutes). At time t=1, there were 75 people remaining in the auditorium. How many people left the auditorium between minutes 1 and 5 ?Which expression can we use to solve the problem?Choose 1 answer:(A) 75+∫15r(t)dt(B) ∫15−r(t)dt(C) 75−∫15r(t)dt(D) ∫r(t)dt
Q. Consider the following problem:The number of people remaining in the auditorium is decreasing at a rate of r(t)=−0.1t people per minute (where t is the time in minutes). At time t=1, there were 75 people remaining in the auditorium. How many people left the auditorium between minutes 1 and 5 ?Which expression can we use to solve the problem?Choose 1 answer:(A) 75+∫15r(t)dt(B) ∫15−r(t)dt(C) 75−∫15r(t)dt(D) ∫r(t)dt
Rate of Change Given: We are given the rate of change of the number of people in the auditorium, r(t)=−0.1t, and we know that at t=1, there were 75 people. To find the number of people who left the auditorium between minutes 1 and 5, we need to integrate the rate of change from t=1 to t=5. This will give us the total change in the number of people during that time period.
Calculate People Left: The correct expression to calculate the number of people who left the auditorium is the integral of the rate of change from t=1 to t=5. Since the rate of change is negative, the integral will give us the decrease in the number of people. We start with 75 people and subtract the number of people who leave.
Expression for Calculation: The correct expression is therefore the initial number of people, 75, minus the integral of the rate of change from t=1 to t=5. This is represented by the expression 75−∫15r(t)dt.
Matching Correct Choice: Looking at the given choices, we can see that option (C) matches the expression we derived: 75−∫15r(t)dt. This is the correct expression to use to solve the problem.
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