Answer:
[tex]2 m/s^2[/tex]
Explanation:
The acceleration of an object (or a person, as in this case) is given by
[tex]a=\frac{v-u}{t}[/tex]
where
v is the final velocity
u is the initial velocity
t is the time interval
In this problem,
u = 20 m/s
v = 40 m/s
t = 10 s
Therefore Jill's acceleration is
[tex]a=\frac{40-20}{10}=2 m/s^2[/tex]
The acceleration of Jill is [tex]\bold{2 \ m / s^{2}}[/tex] if he starts out at the velocity 20 m/s and in 10 s speeds up to 40 m/s.
From given, we came to know that the Jill starts out at 20 m/s, and in 10 s speeds up to 40 m/s, to find acceleration of Jill, we know that acceleration is ratio of velocity to time change.
The acceleration is given by the formula:
[tex]\text { Acceleration }=\frac{\text { Change in velocity }}{\text { Change in time }}[/tex]
We know that change in velocity as 20 m/s to 40.0 m/s and change time as 10 s.
[tex]\Rightarrow \text { Acceleration }=\frac{40-20}{10}[/tex]
[tex]\therefore \text { Acceleration }=2 \ \mathrm{m} / \mathrm{s}^{2}[/tex]
Thus, acceleration of Jill will be [tex]\bold{2 \ m / s^{2}}[/tex]
