David is driving a steady 25.0 when he passes Tina, who is sitting in her car at rest. Tina begins to accelerate at a steady 2.70 at the instant when David passes.
I have tried doing this over and over again, but keep getting it wrong - my answer for 1) comes to be 473047m which is wrong.
Can anyone help me
1)How far does Tina drive before passing David?
2)What is her speed as she passes him?
Thanks!
I have tried doing this over and over again, but keep getting it wrong - my answer for 1) comes to be 473047m which is wrong.
Can anyone help me
1)How far does Tina drive before passing David?
2)What is her speed as she passes him?
Thanks!
-
David position at t seconds after: x1=25t
Tina position at tseconds after: x2=1/2at^2= 1.35t^2
pass: x1=x2
25t= 1.35t^2
t^2-18.52t= 0
t(t-18.52)= 0
t= 18.52[s]
x1= 25t= 25*18.52= 463[m] (1 Ans.)
x2= 1.35t^2= 463[m]
v= v0+at= 0+2.7*18.52= 50[m/s] or 180[km/h] (2 Ans.)
Tina position at tseconds after: x2=1/2at^2= 1.35t^2
pass: x1=x2
25t= 1.35t^2
t^2-18.52t= 0
t(t-18.52)= 0
t= 18.52[s]
x1= 25t= 25*18.52= 463[m] (1 Ans.)
x2= 1.35t^2= 463[m]
v= v0+at= 0+2.7*18.52= 50[m/s] or 180[km/h] (2 Ans.)