Question

9. Two blocks of mass m1 =1 kg and m2 =2kg
are placed in contact on a frictionless
horizontal surface . A force of 10 N is acting on m1.
. What is the acceleration
of m1 and m2
. what is magnitude
of action and reaction forces?
​

Answer 1

Answer :

• Acceleration of m1 and m2 is 3.33 m/s²

• Magnitude of action and reaction forces is 6.67 N

Step-by-step explanation :

GivEn :

• Mass of 1st block (m1) = 1 kg

• Mass of 2ndblock (m2) = 2 kg

• Force applied on 1st block = 10N

To find :

• Acceleration of m1 and m2 = ?

• Magnitude of action and reaction forces = ?

SoluTion :

As we're given with mass and the force applied, let's apply Newton's 2nd & 3rd law to solve this question.

We know that, the net force acting on the system is given by the product of mass and acceleration .

Also, every action in nature has an equal and opposite reaction . [According to the Newton's 3rd law ]

Simply remember that, reaction = -(action )

Now, proceeding towards the question,

Apply Newton's 2nd law,

Acceleration of m1 and m2 :

➟ Force (net) = a × ( m1 + m2 )

➟ 10 = a × ( 1 + 2 )

➟ 10 = a × (3)

➟ a = 10/3

➟ a = 3.33 m/s²

Now,

Apply Newton's 3rd law,

Magnitude(M) of action and reaction forces :

➟ Force (net) - M = m1 × a

➟ 10 - M = 1 × 3.33

➟ M = 10 - 3.33

➟ M = 6.67 N

Hence,

• Acceleration of m1 and m2 is 3.33 m/s²

• Magnitude of action and reaction forces is 6.67 N

Additional information :

❏ Newton's laws of motion relate an object's/particles motion to the forces acting on it .

❏ Newton's 3 laws are stated as :

1. Every object in uniform motion will remain in that state unless any external force is applied on it.

2. Force acting on the system is given by the product of mass and acceleration .

3. For each and every action there is an equal and opposite reaction .