Respuesta :
Given data:
* The distance between the two-goal lines on the football ground is d = 100 yards.
* The player covered the distance while returning is,
[tex]\begin{gathered} d^{\prime}=100-30 \\ d^{\prime}=70\text{ yards} \end{gathered}[/tex]* The time taken by the player in the complete run is t = 25.5 s.
Solution:
(A). The distance traveled by the player during the complete run is,
[tex]\begin{gathered} D=d+d^{\prime} \\ D=100+70 \\ D=170\text{ yards} \end{gathered}[/tex]The average speed of the player is,
[tex]\begin{gathered} s=\frac{D}{t} \\ s=\frac{170}{25.5} \\ s=6.67\text{ yards/s} \end{gathered}[/tex]Thus, the average speed of the player is 6.67 yards/second.
(B). The displacement of the player is,
[tex]D^{\prime}=d-d^{\prime}[/tex]Here, the negative sign is indicating the direction of motion of the player while the return is opposite to the initial direction of motion.
Substituting the known values,
[tex]\begin{gathered} D^{\prime}=100-70 \\ D^{\prime}=30\text{ yards} \end{gathered}[/tex]The average velocity of the player is,
[tex]\begin{gathered} v=\frac{D^{\prime}}{t} \\ v=\frac{30}{25.5} \\ v=1.2\text{ yards/s} \end{gathered}[/tex]Thus, the average velocity of the player is 1.2 yards/second.
