Answer to Question #79643 in Physics for Anonymous

Question

1. A rugby player runs 100. m from his own goal line to the opposing team’s goal line, returning to the halfway line, all in 18.0 s. Calculate (a) his average speed, and (b) the magnitude of his average velocity.

Answer 1

The velocity
v(t)=x^' (t)=2+6t+12t^2
v(2)=2+6×2+12×2^2=62 m/s
The acceleration
a(t)=v^' (t)=6+24t
a(3)=6+24×3=78 m/s^2