Q5.36 The rear side of a truck is open and a box of 40 kg mass is placed 5 m away from the open end as shown in Fig. 5.22. 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 2 m s-2. At what distance from the starting point does the box fall off the truck? (Ignore the size of the box).
Using Newton's second law of motion we can write :
Also, the frictional force is given by :
or
Thus net force acting is : 80 - 60 = 20 N.
The backward acceleration is :
Now using the equation of motion we can write :
or
Thus
And the distance travelled by truck is :
or
or