when it is subjected to a force of $35 N. μs=0.7,μk=0.6 $

Given:

$μ_A = 0 m/s , μ_B = 0 m/s \\ t_A=t_B+5, a_B=5 m/s^2 \\ S = 500 m, a_A= ?$

Ans:

$S=ut+ \dfrac 12 at^2 $

For Car B,

$s_B=u_B.t_B+ \dfrac 12 a_B.t_B^2 \\ 500=0+ \dfrac 12×5×t_B^2 \\ t_B^2=200 \\ t_B=14.14 sec$

For Car A,

$t_A=t_B+5=19.14 sec \\ S_A=u_A.t_A+ \dfrac 12 a_A.t_A^2 \\ 500=0+ \dfrac 12 a_A×19.14^2 \\ a_A=2.73 m/s^2$