In NFL tryouts, a player waits at the starting line, and then accelerates at 4 m/s^2 when the coach yells "go". How fast are they going at the end of the 40 m dash?

Question

Hint: A formula is needed.

Answer 1

Given:

a = 4 m/s^2

treat starting line at Xo = 0 m

treat end of the dash as X = 40m

At starting line the player is at rest Vo = 0 m/s

Find:

Velocity at the end of the dash

V = ?

Solution:

Use constant acceleration equation as a function of position and velocity

2 * a * (X-Xo) + Vo^2 = V^2

2 * 4 * (40-0) + 0 = V^2

320 = V^2

V = 17.88 m/s

Answer 2

v² = u² + 2as

u = 0

s = 40

a = 4

You need to find v