Question

In this problem, you will analyze a system composed of two blocks, 1 and 2, of respective masses m1 and m2. To simplify the analysis, we will make several assumptions:

The blocks can move in only one dimension, namely, along the x axis.
The masses of the blocks remain constant.
The system is closed.
At time t, the x components of the velocity and the acceleration of block 1 are denoted by v1(t) and a1(t). Similarly, the x components of the velocity and acceleration of block 2 are denoted by v2(t)and a2(t).
1. Let us denote the force exerted by block 1 on block 2 by F12, and the force exerted by block 2 on block 1 by F21. If we suppose that m1 is greater than m2, which of the following statements about forces is true?
a. |F12|>|F21|
b. |F21|>|F12|
c. Both forces have equal magnitudes.

Answer 1

c. Both forces have equal magnitudes.

Step-by-step explanation:

According to Newton´s 3rd Law, the force exerted by a body on another one , is equal and opposite to the one that the second object exerts on the first one.

This does not depend on the masses of the objects, so it doesn´t matter that m₁ be greater than m₂.

As examples of this, we can mention the gravity force, the electrostatic force, the normal force, etc.

So, in this case, taking into account only the magnitudes, we can say:

F₁₂ = F₂₁