Question

Mass is the measure of quantity of matter.
A force increases the mass of the body applied on it.
Static friction> rolling friction.
Friction causes wear and tear.
Friction helps in supporting a ladder inclined to a wall.
A force can slowdown a moving body.
True or False ​

Answer 1

Answer:

Friction is a force that opposes the motion of objects; friction can cause objects to slow down. Air resistance is a type of friction. Air resistance causes moving objects to slow down.

Answer 2

Answer:

Explanation:

Balancing forces in horizontal direction,

N  

1

​  

=μN  

2

​  

 

Balancing forces in vertical direction,

N  

2

​  

+μN  

1

​  

=mg

Solving we get,

N  

2

​  

=  

1+μ  

1

​  

μ  

2

​  

 

mg

​  

 

N  

1

​  

=  

1+μ  

1

​  

μ  

2

​  

 

μ  

2

​  

mg

​  

 

Applying rotational equilibrium,

mg  

2

l

​  

cosθ=N  

1

​  

lsinθ+μN  

1

​  

lcosθ  

Solving, tanθ=  

2μ  

2

​  

 

1−μ  

1

​  

μ  

2

​  

 

​  

 

If μ  

1

​  

=0,μ  

2

​  

 



=0

tanθ=  

2μ  

2

​  

 

1

​  

 

N  

1

​  

=μ  

2

​  

mg

or N  

1

​  

tanθ=  

2

mg

​