04-Energy

# 04-Energy - Work& Kinetic Energy F = m a F v i m F v f m...

This preview shows pages 1–7. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Work & Kinetic Energy F = m a F v i m F v f m v f 2 = v i 2 + 2ad F = m (v f 2- v i 2 )/ 2d W o rk F i n a l K i n e t i c E n e r g y In itia l K in e tic E n e rg y d a = (v f 2- v i 2 )/ 2d F d = ½ m (v f 2- v i 2 ) F d = ½ m v f 2- ½ m v i 2 W = (KE) f- (KE) i Work F m ∆x F m ∆x θ Fcosθ W = F ∆x W = (Fcosθ) ∆x W = F . ∆x W = Dot product of F times ∆x Only the component of F parallel to ∆x does work. Fcosθ does do work. Fsinθ does not do work. The component of F perpendicular to ∆x does no work. Work with a Variable Force F x Work = ∫ Fdx ∫ Fdx = Area under the graph of Force vs distance x F F = kx W = ∫ (-kx)dx W = -½ kx 2 This work is stored as potential energy. The potential energy can then be released as kinetic energy. Work = F∆x This is true if F is constant. If F is not constant. F s F s = -kx F S x Conservation of Energy Types of Energy KE = K = ½ mv 2 PE = U U g = mgh U S = - ½ kx 2 TE = Thermal Energy E = K + U + TE E’ = K’ + U’ + TE’ E’ = E K’ + U’ + TE’ = K + U + TE The unit of Work and Energy is the Joule (J). 1J = 1Nm Energy is defined as the ability to do work. Energy is a scalar. Work & Gravitational Potential Energy F h W = F d W = mgh PE = mgh (PE) i = 0 (PE) f = mgh (PE) B = 0 (PE) A = mgh h A v B (KE) A = 0 (KE) B = ½ mv 2 (PE) A + (KE) A = (PE) B + (KE) B (PE) A = (KE) B Conservative Gravitational Field...
View Full Document

{[ snackBarMessage ]}

### Page1 / 18

04-Energy - Work& Kinetic Energy F = m a F v i m F v f m...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online