Question

Blocks with masses of 2kg , 4kg , and 6kg are lined up in a row on a frictionless table. All three are pushed forward by a 52N force applied to the 2kg block. 1. How much force does the 4kg block exert on the 6kg block? 2. How much force does the 4kg block exert on the 2kg block?

Answer 1

Concepts and reason

The concept used to solve the problem is Newton’s second law of motion.

Initially, use Newton’s second law to find the force exerted by on .

Then, use Newton’s second law to find the force exerted by on .

Fundamentals

Newton’s second law states that for a body, “The rate at which its momentum changes is proportional to the net force acting on the body”.

The expression for Newton’s second law is as follows:

$F=ma $

Here, net force acting on a body is , mass of the body is , and acceleration produced on it is .

(1)

The total mass is as follows:

Here, masses in the row are .

Substitute for , for , and for .

The expression for Newton’s second law is as follows:

$F=ma $

Rearrange,

Substitute for and for .

The force exerted by on is as follows:

$F=ma $

Substitute for and for.

(2)

The force exerted on by is as follows:

$F=F-ma $

Substitute for , for , and for.

Ans: Part 1

The force exerted by block on block is .

Part 2

The force exerted by block on block is .