Question

The rear side of a truck is open and a box of $40kg$ mass is placed $5m$ away from the open end as shown in figure. The coefficient of friction between the box and the surface below it is $0.15$. On a straight road, the truck starts from rest and accelerates with $2m{s}^{-2}$. Find the distance (in m) travelled by the truck by the time box falls from the truck. (Ignore the size of the box).

Answer 1

Given Pseudo Force acting on the box $=40\times 2=80N$.

friction force $=\mu N=0.15\times 40\times 10=60N$

$F_{net}=F_p-f=80-60=20N$

Acceleration $a=F_{net}/m=20/40=0.5m/s^2$

Using the equation of motion for uniform accleration

$S=ut+\frac{1}{2}g{t}^2$

As $u=0,t=\sqrt{\frac{2s}{g}}=\sqrt{\frac{2\times 5}{10}}=1s$