Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
Our velocity is 15 m/s, so that is going to be 600 × 15 or 9,000 W, which is 9 × 103 W -- Answer Number 4. 0120
On to Number 5 -- A motor used 120 W of power to raise a 15 N object, so the force required was 15 N in a time of 5 s. 0138
Through what vertical distance was the object raised? 0152
Well, a couple of different ways we could do that here. 0157
If power is force times velocity and velocity in this case is just going to be displacement over time, that will be force times our displacement divided by (t). 0160
We want to solve for the displacement, δy, so I would say δy is power times time divided by force...0175
...which is going to be 120 W × (time) 5 s/15 N (force) so that is going to be 600/15 or 40 m -- Answer Number 3. 0183
Number 6 -- The diagram below shows points (A), (B), and (C) at or near Earth's surface. 0202
As a mass is moved from (A) to (B), 100 J of work are done against gravity. 0210
What is the amount of work done against gravity as an identical mass is moved from (A) to (C)? 0217
Well, as we move from (A) to (C) -- remember gravity is a conservative force; it is independent of the path, so the work done against gravity is going to have to be the same thing because (C) is at the same height as (B), so the correct answer is Number 1, 100 J. 0222
Well, power is going to be work divided by time, but work is force times displacement divided by time. 0299
In this case, the force that the student must overcome is the own weight of the student, so that is going to be mass times acceleration due to gravity times displacement divided by time. 0309
Therefore, power is going to be mass (40 kg), acceleration due to gravity (9.8 m/s2), change in position -- well 5 m in a time of 7 s, so when I put all that together, 40 × 9.8 × 5/7, I get 280 W -- Answer Number 2. 0320
All right, if those went well -- Terrific -- you are ready to move on to the AP level questions and if it did not go so well, now would be a great time to go back and review the unit, the lesson on work and power. 0348
Thanks so much for your time everyone and make it a great day. 0359
The book features an effective, 5-step plan to guide your preparation program and help you build the skills, knowledge, and test-taking confidence you need to succeed. This fully revised edition covers the latest course syllabus and matches the new exam. It also includes access to McGraw-Hill Education’s AP Planner app, which will enable you to customize your own study schedule on your mobile device. It includes a full-length practice AP Physics 1 exam and 3 separate study plans to fit your learning style.
This book is written by our very own Professor Fullerton and features more than 600 worked-out problems with full solutions and deeper understanding questions. AP Physics 1 Essentials covers all major topics included in the AP Physics 1 course, including: kinematics, dynamics, momentum, impulse, gravity, uniform circular motion, rotation, work, energy, power, mechanical waves, sound, electrostatics, and circuits.