3.39 The ball is rolling perpendicular to the sideline of a football field. Suppose, moving uniformly decelerated, the ball rolled 4 m in the first second, and 0.75 m less in the next second. A footballer, initially 10 m away from the ball, started running in the direction of the ball's movement to catch it. Moving uniformly accelerated, the footballer ran 3.5 m in the first second, and 0.5 m more in the next second. How long will it take for the footballer to catch the ball, and will he be able to do so before the ball goes out of bounds, if the footballer needs to run 23 m to reach the sideline?

## Trade and monetary relations
3.39 Instruction. Use the formula $s=v t+a t^{2}$, where $v$ and $a$ are constants. Their values can be calculated from the following conditions: for the ball $s(1)=4, s(2)=7.25$; for the footballer $s(1)=3.5, s(2)=7.5$. Instead of the given formula, the formula for the sum of $n$ terms of an arithmetic progression can also be used, assuming that the desired number $t=n$ is an integer.

Answer: In $5 \mathrm{~s}$; will catch up with the ball 0.5 m before the field line.