Question

A large cube has a mass of 25kg. It is being acclerated

Answer 1

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