Question

A NFL linebacker runs the 100m sprint in 12s. What is his final velocity?

Answer 1

Answer:

Final velocity of NFL line backer is 16.67 m/s.

Explanation:

From the question, we have following data about the NFL line backer:

Initial Speed of line backer = Vi = 0 m/s (Since, he starts from rest)

Distance covered by NFL line backer = s = 100 m

Time taken by the NFL line backer to complete 100 m sprint = t = 12 s

Acceleration of NFL line backer during sprint = a

Final Velocity of NFL line backer = Vf = ?

First we need to find the acceleration of the NFL line backer. For that purpose we will use 2nd equation of motion:

s = (Vi)(t) + (0.5)at²

using values:

100 m = (0 m/s)(12 s) + (0.5)(a)(12 s)²

100 m/72 s² = a

a = 1.39 m/s²

Now, we use 1st equation of motion to find Vf:

Vf = Vi + at

Vf = 0 m/s + (1.39 m/s²)(12 s)

Vf = 16.67 m/s