A cyclist is riding his bike up a mountain trail. When he starts up the trail, he is going [tex]8 \, \text{m/s}[/tex]. As the trail gets steeper, he slows to [tex]3 \, \text{m/s}[/tex] in 1 minute. What is the cyclist's acceleration?

A. [tex]-0.08 \, \text{m/s}^2[/tex]
B. [tex]0.08 \, \text{m/s}^2[/tex]
C. [tex]-12 \, \text{m/s}^2[/tex]
D. [tex]12 \, \text{m/s}^2[/tex]



Answer :

Let's solve the problem step-by-step to find the cyclist's acceleration.

1. Understand the given values:
- Initial velocity ([tex]\( u \)[/tex]): [tex]\( 8 \, \text{m/s} \)[/tex]
- Final velocity ([tex]\( v \)[/tex]): [tex]\( 3 \, \text{m/s} \)[/tex]
- Time ([tex]\( t \)[/tex]): [tex]\( 1 \, \text{minute} \)[/tex]

2. Convert time to seconds:
Since time is given in minutes, we need to convert it to seconds.
[tex]\[ 1 \, \text{minute} = 60 \, \text{seconds} \][/tex]
So, [tex]\( t = 60 \, \text{seconds} \)[/tex].

3. Use the formula for acceleration ([tex]\( a \)[/tex]):
The formula to calculate acceleration is:
[tex]\[ a = \frac{v - u}{t} \][/tex]
where:
- [tex]\( v \)[/tex] is the final velocity.
- [tex]\( u \)[/tex] is the initial velocity.
- [tex]\( t \)[/tex] is the time taken.

4. Substitute the given values into the formula:
[tex]\[ a = \frac{3 \, \text{m/s} - 8 \, \text{m/s}}{60 \, \text{seconds}} \][/tex]

5. Calculate the acceleration:
[tex]\[ a = \frac{-5 \, \text{m/s}}{60 \, \text{seconds}} = -0.08333333333333333 \, \text{m/s}^2 \][/tex]

So, the cyclist's acceleration is [tex]\(-0.08333333333333333 \, \text{m/s}^2\)[/tex].

Among the given options, the closest match to [tex]\(-0.08333333333333333 \, \text{m/s}^2\)[/tex] is:

[tex]\[ -0.08 \, \text{m/s}^2 \][/tex]

Therefore, the correct answer is:
[tex]\[ -0.08 \, \text{m/s}^2 \][/tex]