Question

A ball rolls down a hill. It starts with velocity of 2 ms. After 2 seconds, the ball has a velocity of 12 ms.

What is the acceleration of the ball?

Responses

2 ms2

2 m per s squared

4 ms2

4 m per s squared

5 ms2

5 m per s squared

7 ms2

Answer 1

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

\[
a = \frac{{v_f - v_i}}{{t}}
\]

where:
- \( v_f \) is the final velocity,
- \( v_i \) is the initial velocity,
- \( t \) is the time.

From the problem:
- Initial velocity, \( v_i = 2 \, \text{ms}^{-1} \)
- Final velocity, \( v_f = 12 \, \text{ms}^{-1} \)
- Time, \( t = 2 \, \text{s} \)

Now substituting the values into the equation:

\[
a = \frac{{12 \, \text{ms}^{-1} - 2 \, \text{ms}^{-1}}}{{2 \, \text{s}}}
\]

\[
a = \frac{{10 \, \text{ms}^{-1}}}{{2 \, \text{s}}}
\]

\[
a = 5 \, \text{ms}^{-2}
\]

So, the acceleration of the ball is **5 m/s²**.