Energy Seo Physics

Objectives To find how energy conserves and converts to other forms To apply understanding of storing and moving energy

Energy is always conserved Units? Joules (J) 2 main categories : What is Energy? (E) aka. Storage Mechanism change in Work (ΔW) Energy is always conserved Units? Joules (J) 2 main categories : Kinetic and Potential

Kinetic Energy 5 different forms What is Kinetic Energy? (Ek or EKE) Energy of motion Equation? KE = ½ x m x v2 m=mass; v=velocity Units? Joules (J) 5 different forms mechanical, electrical, thermal, electromagnetic, and light

Practice What is the Kinetic Energy of a 150 kg object that is moving with a speed of 15 m/s?

DIY What is the Kinetic Energy of a 478 kg object that is moving with a speed of 15 m/s?

Potential Energy Units? 5 Forms of Potential Energy What is Potential Energy? (EP or EGP) Stored energy Energy of position Equation? GPE = m x g x h m= mass; g=gravity; h=height Units? Joules (J) 5 Forms of Potential Energy Chemical, Elastic, Electric, Magnetic and Nuclear

Practice g=9.8 m/s2 GPE= mgh GPE= 10 kg x 9.8 m/s2 x 4 m 392 J What is the Gravitational Potential Energy of a 10.0 kg object at 4.00 m above the ground? g=9.8 m/s2 GPE= mgh GPE= 10 kg x 9.8 m/s2 x 4 m 392 J

Elastic Potential Energy What is EPE? (EEL or EEP) Energy stored in a stretched or compressed spring. Equation? k= Spring constant (units: N/m) x= distance of stretch /compression in spring Units? Joules (J)

Practice A 1 kg crate is suspended on a spring. How much elastic potential energy is stored in the spring if the pear stretches the spring 0.204 m? k= 9.6 N/m

Chemical Potential Energy? What is CPE? (ECh) Energy stored during bonding between molecules Released from chemical reactions Ex. Burning, Fuels, Battery, and Heaters

Mechanical Energy What is a Mechanical Energy? (ME) Equation? The total of Kinetic and Potential Energy Equation? ME = KE + PE Describes how energy is stored and used

Energy Pie Charts 1. Determine Energy forms for the scenario   2. Draw a pie graph for number of pictures shown per frame 3. Show energy storages changing for different frames EX.

Pie Chart Practice A moving cart slows slightly as it rolls toward a spring, and then comes to a stop by compressing the spring. Sketch energy pie charts representing energy storage for each stage

Conservation of Energy What is Conservation of Energy? Energy is conserved from one form to another Will not losing original energy Energy cannot be created or destroyed Total amount of energy never changes Equation Format Ei1+ Ei2 = Ef1+ Ef2

The total initial energy must equal the total final energy. LOL Bar Charts Helps us analyze the energy transfer The total initial energy must equal the total final energy.

LOL Bar Chart Practice Suppose a cart is speeding on the highway, initially. Towards the end, it bounces off to a spring bumper and slows down