# Question 3e169

Jul 10, 2017

${a}_{x} = 1.23$ ${\text{m/s}}^{2}$

#### Explanation:

I'll assume he started from rest, and the acceleration is constant.

We can solve this problem using the kinematics equation

${v}_{x} = {v}_{0 x} + {a}_{x} t$

where

• ${v}_{x}$ is the velocity (one-dimensional) at time $t$

• ${v}_{0 x}$ is the initial velocity

• ${a}_{x}$ is the constant acceleration

• $t$ is the time

He starts with an initial velocity of $0$ (assuming he started from a state of rest), so plugging in known values, we have

$11.1$ $\text{m/s}$ $= 0 + {a}_{x} \text{(} 9$ $\text{s)}$

a_x = color(red)(1.23 color(red)("m/s"^2

His (assumed to be constant) acceleration is thus color(red)(1.23 sfcolor(red)("meters per second per second"#.