Question

A football player stands up from the bench, walks to the side of the field, and sprints onto the field. Which of the following changes in gait would you not see as he transitions from walking to running?

a.Large increase in stride frequency
b.Disappearance of double support
c.Increase in stride length
d.Appearance of an aerial phase

Answer 1

The average velocity of the quarterback for the first interval is 6.0 m/s, the second interval is -1.71 m/s, the third interval is 4.04 m/s, and for the entire motion is approximately 3.49 m/s forward.

Step-by-step explanation:

The student is asking for the calculation of the average velocity for a football quarterback during different intervals of play and for the entire motion. The concept of average velocity is essential in kinematics, a branch of mechanics in Physics. To find average velocity, we take the total displacement divided by the total time for the interval in question.

Calculation for Each Interval:

1. First interval: Average velocity = displacement/time = 15.0 m / 2.50 s = 6.0 m/s, forward.
2. Second interval: Average velocity = displacement/time = -3.00 m / 1.75 s = -1.71 m/s, backward.
3. Third interval: Average velocity = displacement/time = 21.0 m / 5.20 s = 4.04 m/s, forward.

Calculation for Entire Motion:

Average velocity for the entire motion = total displacement / total time. The total displacement is the sum of individual displacements: 15.0 m - 3.0 m + 21.0 m = 33.0 m. The total time is the sum of individual times: 2.50 s + 1.75 s + 5.20 s = 9.45 s. Therefore, the quarterback's average velocity for the entire motion is 33.0 m / 9.45 s ≈ 3.49 m/s, forward.