Final answer:
The running back's current position is 51 yards from the starting point after running at 9 yd/s for 4 seconds, starting from the 15-yard line.
Step-by-step explanation:
The student is asking about the position of a running back in a football game after running up the field for a certain amount of time at a given speed. Initially, the running back is at the 15-yard line and runs toward the 60-yard line at 9 yards per second for 4 seconds.
To calculate the running back's current position, we use the formula:
Distance = Speed × Time
By plugging in the values:
Distance = 9 yd/s × 4 s = 36 yards
Now, we add the distance he ran to his starting position:
Current Position = Starting Position + Distance Ran
Current Position = 15 yards + 36 yards = 51 yards
Therefore, the running back's current position is 51 yards from the starting point, which means the correct answer is (c) 51 yards from the starting point.