A 150-kg object takes 1.5 minutes to travel a 2,500-meter straight path. It begins the trip traveling at 120 meters per second and decelerates to a velocity of 20 meters per second.

What was its acceleration?

A. [tex]$-1.11 \, \text{m/s}^2$[/tex]
B. [tex]$-0.3 \, \text{m/s}^2$[/tex]
C. [tex]$+1.11 \, \text{m/s}^2$[/tex]
D. [tex]$+80 \, \text{m/s}^2$[/tex]

To find the acceleration, we can use the formula for acceleration, which is:

[tex]\[
\text{acceleration} = \frac{\text{final velocity} - \text{initial velocity}}{\text{time}}
\][/tex]

Let's break down the solution step-by-step based on the information given:

1. Identify the initial and final velocities:
- The initial velocity ([tex]$v_i$[/tex]) of the object is 120 meters per second.
- The final velocity ([tex]$v_f$[/tex]) of the object is 20 meters per second.

2. Convert the time from minutes to seconds:
- The object travels for 1.5 minutes. To work with the velocities in meters per second, we need to convert this time into seconds.
- Since there are 60 seconds in a minute, the time in seconds is:
[tex]\[
1.5 \, \text{minutes} \times 60 \, \text{seconds/minute} = 90 \, \text{seconds}
\][/tex]

3. Calculate the acceleration:
- Use the acceleration formula with the values identified:
[tex]\[
\text{acceleration} = \frac{20 \, \text{m/s} - 120 \, \text{m/s}}{90 \, \text{seconds}}
\][/tex]
- Simplify the expression:
[tex]\[
\text{acceleration} = \frac{-100 \, \text{m/s}}{90 \, \text{seconds}} = -1.1111 \ldots \, \text{m/s}^2
\][/tex]

Therefore, the acceleration is approximately [tex]$-1.11 \, \text{m/s}^2$[/tex].

So the correct answer is [tex]$-1.11 \, \text{m/s}^2$[/tex].