Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store
seo-qna
SearchIcon
banner

Two blocks m1 and m2 are resting on a rough inclined plane of inclination 370 as shown in figure. The contact force between the blocks is, (m1=4Kg,m2=2Kg,μ1=0.8,μ2=0.5,g=10m/s2,sin37=3/5)
seo images


(A) 3.2N
(B) 3.6N
(C) 7.2N
(D) Zero

Answer
VerifiedVerified
486.6k+ views
like imagedislike image
Hint:Use the formula of the newton’s second law and from the free body diagram find the acceleration of the blocks over the inclined surface. To find the contact force between blocks, again substitute the same formula for the second block and substitute the value of the acceleration.

Useful formula:
The formula of the newton’s second law of motion is given by
F=ma
Where F is the force, m is the mass and a is the acceleration.

Complete step by step solution:
It is given that the mass of the first block, m1=4Kg
Mass of the second block, m2=2Kg
The coefficient of friction of the first block, μ1=0.8
The coefficient of friction of the second block, μ2=0.5
The angle of the inclined surface with the horizontal, θ=37
Since the coefficient of friction of the first block is more than the coefficient of the fiction of the second block, then both are said to have the same acceleration. Hence
seo images

a1=a2=a
So let us consider two blocks as the single block with the mass 3Kg . Separating this force into horizontal and the vertical component.
By rearranging the formula, we get
a=Fm
Substituting the values,
a=6gsin37(f1+f2)6
Where f=μmgcosθ
a=6gsin37(0.8×2×10cos37+0.5×4×10cos37)6
By simplifying the above equation,
a=3627.556
By further simplification, we get
a=1.41ms2
seo images

Let us consider the force acts on the first block to find the contact force between them,
By using the formula again,
F=ma
2×10sin370+Nf1=2×a
By simplifying,
N=2.84+12.2412=3.2N
Hence the contact force between the block is 3.2N .

Thus the option (A) is correct.


Note:Remember that the mass and the gravitational force acts in the direction of the motion of the block whereas the frictional force acts against the motion. Since the second block is located below the first block, the whole force on the first block acts on the second, hence the second block is considered to find the force of contact.
Latest Vedantu courses for you
Grade 10 | ICSE | SCHOOL | English
Vedantu ICSE 10 Pro Course (2025-26)
calendar iconAcademic year 2025-26
language iconENGLISH
book iconUnlimited access till final school exam
tick
School Full course for ICSE students
PhysicsPhysics
BiologyBiology
ChemistryChemistry
MathsMaths
₹41,000 (9% Off)
₹37,300 per year
Select and buy