One more newton laws

Object A placed on a floor frictionless and object B placed on object A.
The drag coefficient between A & B is 0.3
The length of A is 1m and the length of B is 30 cm .
a force of 100N workin on object B.
What is the time take to the edge of object B placed on the edge of object A ?

all i received its that acceleration of B a = 7.06

TNX

ohh i forgat :
mA=20kg
mB=10kg

somebody ???

plz

How did you calculated the acceleration?

Remember that in case of a linear motion: s =1/2*a*t^2.

$$\Sigma_F_=ma$$
f=ma
mBg*0.3=ma

PhanthomJay
$$\Sigma_F_=ma$$