Question

A force of 20N is pushing two blocks horizontally along a frictionless floor. What is the force that the B block exerts on A block mass of A are 8 kg and 2 kg respectively.

Answer 1

Answer on Question 50003, Physics, Mechanics | Kinematics | Dynamics

Question:

A force of 20N is pushing two blocks horizontally along a frictionless floor. What is the force that the B block exerts on A block mass of A are 8 kg and 2 kg respectively.

Solution:

Let us obtain the acceleration of the system of the blocks A and B. By the definition of the Newton's Second Law of motion we have:

$$a = \frac {F}{m _ {1} + m _ {2}} = \frac {2 0 N}{8 k g + 2 k g} = 2 \frac {m}{s ^ {2}}.$$

As we know the acceleration we can obtain the force that the B block exerts on the A block:

$$F _ {B} = m _ {B} a = 2 k g \cdot 2 \frac {m}{s ^ {2}} = 4 N.$$

Answer:

$$F _ {B} = 4 N.$$