--- ## Impulse - A **collision** in physics is a short duration interaction between two objects. There are three phases to a collision: - The first phase begins at **the moment of contact between the two objects**. The second phase occurs at the moment of *"maximum compression"* which occurs when then objects in contact **are the most deformed**. The final *"phase"* of a collision occurs at the moment when the **contact between the two objects ends. - If we graph **time vs force** for a collision we will see a very large **spike** in the graph since a large force was exerted over a small period of time. A **large force exerted during a short interval of time like this is called an ==impulsive force==**. - We can quantify the "effect" of an **impulsive force** by finding the **area under this force versus time curve**. This area is known as the **impulse (J)** of the force. - To find this area **without using [[Integration]] we can find the area under a line representing the average force exerted** over that same duration. Surprisingly this area is exactly the same as the area under the **actual curve**. - Impulse is given in units of $\small N\cdot s$ (newtons per second *also known as joules*) and is commonly denoted using the variable $\small J$. - Since the force exerted on an object can be either **positive or negative** the impulse exerted onto an object can also be either **positive or negative** *(depending on the direction)*. ==Therefore we say that impulse is a **vector quantity.**== $\newline$ $\text{Impulse J = are under the force curve }=F_{avg}\;\cdot\;\Delta t$ $\color{grey}\small\text{impulse due to a force acting for a duration }\Delta t$ $\newline$ >[!quote] >##### *Time vs force graph* ![[Momentumimpulsegraph.png|850]] >##### *Finding total impulse in Jules (J)* >![[Momentumde.png|324]]![[Momentumswe.png|525]] ##### *The impulse approximation* - When two object interact during a collision the force of the collision between those two objects **are usually quite large**. In fact, this force is usually large enough that we can reasonably **ignore all the other, *smaller* forces that act on the objects throughout the interaction** without it having a significant effect on our calculations. - Choosing to ignore the smaller secondary forces *(during a collision)* for the purpose of **simplifying calculations** is known as **"impulse approximation"**. --- ## Calculator <iframe src="https://app.calconic.com/api/embed/calculator/6489b45928c7470029d3e8cf" sandbox="allow-same-origin allow-forms allow-scripts allow-top-navigation allow-popups-to-escape-sandbox allow-popups" title="Calconic_ Calculator" name="Calconic_ Calculator" height="900" scrolling="no" style="width: 100%; border: 0; outline: none;"></iframe>