Momentum • Momentum is "mass in motion." • All objects have mass; so if an object is moving, then it has momentum. • Momentum depends upon mass and velocity. • Momentum is a vector. (Has direction) • Momentum = mass • velocity p=m•v units kg m/s Momentum Answer the following What is momentum? What variables are involved in your definition? How are they related? Could the butterfly and the 18-wheeler ever have the same momentum? Why or why not? Momentum Stop @ (2min mark) Impulse Changing Newton’s 2 nd F=ma F = m (Vf – Vi) t F t = m (Vf – Vi) Law Notes: Impulse This equation is called the Impulse Momentum Equation but it should be called Impulse CHANGE in Momentum Impulse = force·time Impulse = mass·∆velocity Impulse = change in momentum J = F t= m(Vf – Vi )= Δp J = impulse (N·s) m =mass (kg) v = velocity (m/s) F = force (N) t = time (s) p = momentum (kg·m/s) IMPULSE is the product of a FORCE and the TIME over which it acts. impulse = F t A CHANGE IN MOMENTUM is simply the difference between the Final Momentum and the Initial Momentum change in momentum = m (Vf – Vi) Crash Videos Honda Goldwing AirBag AirBag Vest Saves Life Bicycle Safety Helmet Safety Sphere Tesla Crash Test Crash Video Bozeman Science Impulse Video ❖ ❖ Take notes in your composition book and work out Car Crash practice problem by pausing the video before he shows the answer. Write down a small summary about the main idea of the video