Answer:
p= 400.29N ........the horizontal force
Explanation:
Given data
mass=25 kg
small cube mass mass=4 kg
Us (The Coefficient of static b/w two cubes) = 0.71
to find
The horizontal force to keep the small cube from sliding downward
Solution
F=ma.........................from Newton Second law
Where F=force
a=acceleration
m=mass
we can write equation in form of acceleration
a=F/m
The acceleration on small box is same as that on the large box.
Let P be force to find.
then:
a=p/(25kg+4kg)
a=p/(29kg)m/s²
The force acting on small box:
F=ma
f=4*(p/29)N........................normal force
friction force= Us*(normal force).........where Us is coefficient of static friction.
friction force= 0.71*(4*p/29)
Now to find weight
weight= mg
weight= 4*9.8
for the object(small box) not to slide down the friction force b/w the two objects have to be exactly the same as the weight of the object.
0.71*(4*p/29)=4*9.8
solving for p(force)
p= 400.29N ........the horizontal force
