The second instalment in this thrilling trilogy! Let’s get to it, shall we! (I’ll now refrain from using exclamation marks…)

Newton’s Second Law states that:

The **resultant force of an object** is **proportional** to the **rate of change of momentum** of the object, and the **momentum change** takes place in the **direction of the force**.

This law effectively states the **total force upon an object will increase/ decrease** as **rate of change of momentum change**s. The momentum also **gains direction** from **the direction of the force**. I have to admit, this law is a little less straight forward than the first and third but I’ll try my best to explain it.

An equation that underpins Newton’s Second Law is:

# F = ma

**F – Resultant Force (N)****m – Mass (kg)****a – acceleration (ms^-2)**

From this, we can begin to make more sense of the second law. Force **causes an object to accelerate** in a **certain direction** which is effectively what is going on when we say that the momentum change takes place in the direction of force. For **momentum to change the velocity must increase** (**Easier than altering the mass**) **via acceleration** which is where we see the **link strengthen** (**Or, at least, I do**). The **Resultant force causes acceleration** which **consequently changes the velocity and the momentum in the direction of the force**.

Summary

- Newton’s Second Law – The resultant force of an object is proportional to the rate of change of momentum of the object, and the momentum change takes place in the direction of the force.
- F = ma – Helps to explain the law
- Resultant force – causes acceleration
- Acceleration – causes increase in velocity over time
- Increased Velocity over time – change of momentum over time
- Change of momentum over time – Newton’s Second Law

I hope that explanation was understandable (I couldn’t think of a relevant superhero example which, I imagine, for some may be a relief) and that you now have a better grasp of Newton’s Second Law. As always, please leave all thoughts, questions, feedback and requests in the comment section and I will get back to you as soon as I can. Thank you.

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