A marker is rolled horizontally off the top of a table. After 5 seconds the marker lands on the ground with a final velocity of −2.5 m/s. Which kinematic equation would be most useful for finding the ball’s initial velocity? (Assume a= −9.8 m/s^2) (1 point)

Answer 1

To find the initial velocity of the marker that was rolled off the top of the table, you can use the following kinematic equation that relates initial velocity, final velocity, acceleration, and time:

\[ v_f = v_i + a t \]

Where:

• \( v_f \) is the final velocity (-2.5 m/s),
• \( v_i \) is the initial velocity (what we need to find),
• \( a \) is the acceleration (-9.8 m/s²),
• \( t \) is the time (5 seconds).

Rearranging the equation to solve for the initial velocity (\( v_i \)) gives:

\[ v_i = v_f - a t \]

You can then substitute the known values into the equation to solve for \( v_i \). This equation is most useful for finding the initial velocity in this scenario.