Question

A football quarterback runs 12.1 m straight down the playing field in 2.50 s. He is then hit and pushed 3.00 m straight backward in 2.30 s. He breaks the tackle and runs straight forward another 18.3 m in 5.20 s. Calculate his average velocity for each of the three intervals and for the entire motion. (Define the positive direction to be the direction of initial motion.)

Answer 1

given,

Case 1: Football straight run 12.1 m for 2.50 s

Case 2: Football moves backward 3 m for 2.30 s

Case 3: Football again move forward 18.3 m for 5.20 s.

Speed on the Three cases,

Case 1

`v_1 = (12.1)/(2.50)`

v₁ = 4.84 m/s

Case 2

`v_2 = (-3)/(2.30)`

v₂ = -1.30 m/s

Case 3

`v_3 = (18.3)/(5.20)`

v₃ = 3.45 m/s

now, Average velocity of the entire motion

`v_(avg)=(total\ distnace)/(total\ time)`

`v_(avg)=(12.1-3+18.3)/(2.50+2.30+5.20)`

`v_(avg)=(27.4)/(10)`

`v_(avg) = 2.74\ m/s`