A ping pong ball is rolling across a table top at 22 m/s. If it is 71 m away from the edge, how much acceleration does a person blowing on it need to apply to stop it from falling if they blow for 8.7 seconds?

To find the acceleration needed to stop the ping pong ball, we can use the kinematic equation:

v = u + at,

where:
v = final velocity (in this case, 0 m/s since we want to stop the ball from falling),
u = initial velocity (given as 22 m/s),
t = time taken (given as 8.7 seconds).

First, let's rearrange the equation to solve for acceleration (a):

a = (v - u) / t.

Substituting the given values:

a = (0 - 22) / 8.7.

Now, we can calculate the value of acceleration:

a ≈ -2.5287 m/s².

Since acceleration is a vector, the negative sign indicates that the acceleration is in the opposite direction of the initial velocity.