Question

Could you explain why the value of horizontal velocity 10m/s is subtituted to the position of a(acceleration) in question (ii)?

Answer 1

In question (ii), we need to calculate the vertical velocity when the ball strikes the floor.

The initial vertical velocity is equal to 0, since the ball is moving on the table with only horizontal velocity.

The acceleration in the vertical motion will be the gravity acceleration, which is equal to 10 m/s².

Then, using Torricelli's equation, we can find the final vertical velocity:

`\begin{gathered} V_f^2=V_i^2+2\cdot a\cdot s\\ \\ V_f^2=0+2\cdot10\cdot1\\ \\ V_f^2=20\\ \\ V_f=4.47\text{ m/s} \end{gathered}`