# Work and Energy – Physics 101 / AP Physics 1 Review with Dianna Cowern

From Physics Girl.

Lesson 9 (Work and Energy) of Dianna’s Intro Physics Class on Physics Girl. Never taken physics before? Want to learn the basics of physics? Need an AP Physics 1 review before the exam? This course is for you!

Exercises in this video:
1. A rocket pushes a space cow, from rest, with a Force of 100N, over a distance of 10m. How much work did the rocket do? What is the final kinetic energy of the cow? How fast is the cow moving?

2. You lift a 10kg cow, with a constant velocity, 10m up. How much work did you do? How much potential energy is stored in the gravitational field?

3. You drop the cow 10m onto a big cow airbag. How fast was the cow moving right before she hit the airbag? How fast would a cow with twice as massive be moving with the same setup?

4. A giant wrecking ball with 80kg mass, is dropped from a height of 35m. It bounces off of a trampoline and reaches a height of 14m on the return trip. How much energy was lost to heat in the bounce?

5. A square cow slides down a frictionless ramp, starting at a height h above the ground. At the bottom the cow starts sliding along the ground. How far does the cow slide, in terms of m, g, h, and u, where u is the coefficient of friction between the cow and the ground? [u is mu]

Special thanks to Mark Rober for his encouraging shoutout and to Simone Giertz for letting me almost hit myself in the face with a bowling ball at her workshop.

Credits:
Dianna Cowern – Executive Producer/Host/Writer
Jeff Brock – Lead Writer/Course Designer
Laura Chernikoff – Producer
Kaitlyn Ali – Video Editor
Sophia Chen – Researcher/Writer
Erika K. Carlson – Researcher/Writer
Hope Butner – Production Assistant
Levi Butner – Videographer
Lauren Ivy – Set Design
Vanessa Hill – Consulting Producer
Aleeza McCant – Illustrator
Rachel Allen – Illustrator
Consultant – Kyle Kitzmiller
Lucy Brock, Samantha Ward – Curriculum Consultants
Cathy Cowern – Transcription