Final answer:
To calculate the average force exerted by the tackler on the 90kg quarterback, we can use Newton's second law of motion, which states that force (F) equals mass (m) times acceleration (a). The average force exerted by the tackler on the quarterback is -90 N.
Step-by-step explanation:
To calculate the average force exerted by the tackler on the 90kg quarterback, we can use Newton's second law of motion, which states that force (F) equals mass (m) times acceleration (a).
First, we need to find the acceleration of the quarterback. We can use the equation a = (final velocity - initial velocity) / time.
The final velocity is 0 m/s (as the quarterback is stopped) and the initial velocity is 4 m/s. The time taken is 4 seconds.
Therefore, the acceleration is (0 - 4) m/s / 4 s = -1 m/s² (negative because the quarterback is decelerating).
Now, using the formula F = m * a, we can calculate the average force exerted by the tackler.
F = 90kg * (-1m/s²) = -90 N
The average force exerted by the tackler on the quarterback is -90 N.