Uploaded September 2020 | Updated September 2026, 3 weeks ago
Lesson 4 (Newton's Laws of Motion) 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:
Problem 1: You push your square space cow, mass 5kg, with a force of 10N. What will be the acceleration of your space cow?
Problem 2: Your tiny cow has a mass of 1kg and is standing in a field in Kansas. What force does Earth’s gravity exert on the cow?
Problem 3: You are suspending two cows from the ceiling, one below the other. You have really strange hobbies. The lower cow has a mass of 2kg. The upper cow has a mass of 1kg. What is the tension in the rope between the top cow and the ceiling?
Problem 4: Now you have two square cows, one mass 4kg, the other mass 2kg, lined up on a frictionless surface. You push on the first cow such that the two cows accelerate at 2 m/s^2. What force does the second cow exert on the first?
Special thank you to astrophysicist and folklorist Moiya McTier for her shoutout at the end of the video! Find Moiya on Twitter @GoAstroMo
Dianna Cowern - Executive Producer/Host/Writer
Jeff Brock - Lead Writer/Course Designer
Laura Chernikoff - Producer
Victoria C. Page - Video Editor
Sophia Chen - Researcher/Writer
Erika K. Carlson - Researcher/Writer
Levi Butner - Videographer
Hope Butner - Production Assistant
Darren Dyk - Slow Motion Cinematography
Andy Brown - Curriculum Consultant
Lauren Ivy - Set Design
Vanessa Hill - Consulting Producer
Aleeza McCant - Illustrator
Alicia Cowern - Transcription
Consultant - Kyle Kitzmiller
Lucy Brock, Samantha Ward - Curriculum Consultants
Lesson 4 (Newton's Laws of Motion) 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:
Problem 1: You push your square space cow, mass 5kg, with a force of 10N. What will be the acceleration of your space cow?
Problem 2: Your tiny cow has a mass of 1kg and is standing in a field in Kansas. What force does Earth’s gravity exert on the cow?
Problem 3: You are suspending two cows from the ceiling, one below the other. You have really strange hobbies. The lower cow has a mass of 2kg. The upper cow has a mass of 1kg. What is the tension in the rope between the top cow and the ceiling?
Problem 4: Now you have two square cows, one mass 4kg, the other mass 2kg, lined up on a frictionless surface. You push on the first cow such that the two cows accelerate at 2 m/s^2. What force does the second cow exert on the first?
Special thank you to astrophysicist and folklorist Moiya McTier for her shoutout at the end of the video! Find Moiya on Twitter @GoAstroMo
Dianna Cowern - Executive Producer/Host/Writer
Jeff Brock - Lead Writer/Course Designer
Laura Chernikoff - Producer
Victoria C. Page - Video Editor
Sophia Chen - Researcher/Writer
Erika K. Carlson - Researcher/Writer
Levi Butner - Videographer
Hope Butner - Production Assistant
Darren Dyk - Slow Motion Cinematography
Andy Brown - Curriculum Consultant
Lauren Ivy - Set Design
Vanessa Hill - Consulting Producer
Aleeza McCant - Illustrator
Alicia Cowern - Transcription
Consultant - Kyle Kitzmiller
Lucy Brock, Samantha Ward - Curriculum Consultants

![Work and Energy - Physics 101 / AP Physics 1 Review with Dianna Cowern
Lesson 9 (Work and Energy) of Diannas 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 Work and Energy - Physics 101 / AP Physics 1 Review with Dianna Cowern](https://i.ytimg.com/vi/rKwK06stPS8/mqdefault.jpg)






![The universe is SPEEDING UP
This never-before-seen footage of Dianna was taken when we went to Mammoth California to film two videos about the expansion of the universe. Dianna is still sick and wont return for a long time, so enjoy this science explanation like the good old days.
If you want to support Dianna during her recovery, you can do so on Patreon where we post content like this more often. → [https://www.patreon.com/physicsgirl]
Watch the full video - https://www.youtube.com/watch?v=q67vH0SKahU&ab_channel=PhysicsGirl
2nd video - https://www.youtube.com/watch?v=I9q-7GPQr1Y&ab_channel=PhysicsGirl
Special thank you to our X-Ray tier patrons: Anton Ragin, Lydia Fullard, zoddy, dheeraj mekala, David Johnston, Christopher Kemsley, Adrian Archuleta, Zoran Dekic, Austin Rose, Gnare, Bazinga_X, Gil Chesterton, Mike Schneider, marcss, James Prokop, Carlos Patricio, Tommy Joseph, jeremy glowacki, Vishal Bedi, Matt Kaminski, Andrew Herstek, Vincent Argiro, Eddie Sabbah, Patrick Olson, Chris Wyma, Zalster, David Cichowski, Vikram Bhat, Margaux Lopez, Edi, Kenneth Hunter, Fabrice Eap, Joe Pacheco
Creator/Host: Dianna Cowern
Editor: Levi Butner
http://physicsgirl.org/
http://twitter.com/thephysicsgirl
http://facebook.com/thephysicsgirl
http://instagram.com/thephysicsgirl
Music provided by APM
https://www.apmmusic.com/ The universe is SPEEDING UP](https://i.ytimg.com/vi/sOhdQNjmK_U/mqdefault.jpg)


Special thank you to our X-Ray tier patrons: Carlos Patricio, David Cichowski, Eddie Sabbah, Fabrice Eap, Gil Chesterton, Isabel Herstek, Margaux Lopez, Matt Kaminski, Michael Schneider, Patrick Olson, Vikram Bhat, Vincent Argiro, wc993219
Creator/Host: Dianna Cowern
Editor: Levi Butner
#shorts Worlds highest ball bounce!](https://i.ytimg.com/vi/u3BKM9vbZDA/mqdefault.jpg)