Question

If Jill starts out at 20 m/s, and in 10 s speeds up to 40 m/s, what is her acceleration?

Answer 1

Answer:

$2 m/s^2$

Explanation:

The acceleration of an object (or a person, as in this case) is given by

$a=\frac{v-u}{t}$

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

$a=\frac{40-20}{10}=2 m/s^2$

Answer 2

Answer:

The acceleration of Jill is $\bold{2 \ m / s^{2}}$ if he starts out at the velocity 20 m/s and in 10 s speeds up to 40 m/s.

Explanation:

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:

$\text { Acceleration }=\frac{\text { Change in velocity }}{\text { Change in time }}$

We know that change in velocity as 20 m/s to 40.0 m/s and change time as 10 s.

$\Rightarrow \text { Acceleration }=\frac{40-20}{10}$

$\therefore \text { Acceleration }=2 \ \mathrm{m} / \mathrm{s}^{2}$

Thus, acceleration of Jill will be $\bold{2 \ m / s^{2}}$