Christian went on a run. He jogged for five minutes, then increased his rate to a faster constant pace for seven minutes. He then took a rest for four minutes. During what time interval has Christian traveled 1.5 miles?

(1 point)
Christian traveled 1.5 miles from blank≤t≤blank

1 answer

To find the time interval in which Christian traveled 1.5 miles, we need to break down his run into segments and calculate how far he traveled in each segment.

  1. First Segment (Jogging for 5 minutes): We don't have the jogging speed given, so let's denote it as \( r_1 \) miles per minute.

    Distance traveled in the first segment: \[ \text{Distance}_1 = r_1 \times 5 , \text{minutes} = 5r_1 , \text{miles} \]

  2. Second Segment (Faster pace for 7 minutes): Let's denote his faster pace as \( r_2 \) miles per minute.

    Distance traveled in the second segment: \[ \text{Distance}_2 = r_2 \times 7 , \text{minutes} = 7r_2 , \text{miles} \]

  3. During rest (4 minutes): During the rest, Christian does not travel any distance.

To find when he has traveled a total of 1.5 miles, we need to combine these distances:

Case 1: If he traveled 1.5 miles during the first segment only

We set the distance of the first segment equal to 1.5 miles: \[ 5r_1 = 1.5 \Rightarrow r_1 = \frac{1.5}{5} = 0.3 , \text{miles per minute} \]

This scenario is possible only if he traveled 1.5 miles in the first 5 minutes.

Case 2: If he traveled a portion in the first segment and then completed 1.5 miles in the second segment

Now, we will assume he traveled \( D_1 = 5r_1 \) in the first segment and \( D_2 = 7r_2 \) in the second segment such that: \[ D_1 + D_2 = 1.5 \] We can solve for distances but without exact rates, we can't get specific numbers.

However, if \( t = 5 + 7 = 12 \) minutes gives him exactly 1.5 miles, then we can find for intervals.

Assuming he travels enough in the second segment to surpass 1.5 miles:

Since Christian jogged for 5 minutes and then went faster for 7 minutes:

Total time interval:

  • From \( t = 0 \) to \( t = 12 \) minutes for both segments, if he covered the distance adequately.
Result:

Christian traveled 1.5 miles during the time interval: \[ 0 \leq t \leq 12 \]

Thus, Christian traveled 1.5 miles from 0 ≤ t ≤ 12 minutes.