This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: fryer (vdf96) Assignment 1 Force and Vector Addition graves (6) 1 This print-out should have 24 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 (part 1 of 2) 10.0 points A book is at rest on an incline as shown below. A hand, in contact with the top of the book, produces a constant force F hand vertically downward. F hand B o o k The following figures show several attempts at drawing free-body diagrams for the book. Which figure has the correct directions for each force? The magnitudes of the forces are not necessarily drawn to scale. 1. weight normal friction force 2. weight force normal friction 3. normal friction weight force 4. weight force friction normal correct 5. weight friction normal force 6. weight friction force normal 7. normal force friction weight 8. weight force normal friction Explanation: The normal force points perpendicular to the surface of the inclined plane. The weight force points down. The F hand also points down. The friction force keeps the book from sliding and consequently points up the incline. fryer (vdf96) Assignment 1 Force and Vector Addition graves (6) 2 002 (part 2 of 2) 10.0 points For the normal force exerted on the book by the wedge in the diagram, which force(s) complete(s) the force pair for Newtons third law (action-reaction)? 1. the component of F hand pointing perpen- dicular to the surface of the incline 2. the normal force exerted on the wedge by the book correct 3. the component of gravity pointing parallel to the surface of the incline 4. the component of gravity pointing per- pendicular to the surface of the incline 5. the pull of the book on the earth 6. the sum of the component of gravity per- pendicular to the surface of the incline and the component of F hand perpendicular to the surface of the incline 7. the pull of the earth on the book Explanation: The force that completes the third law pair with the normal force of the wedge on the book is the normal force of the book on the wedge. The the sum of the component of gravity perpendicular to the surface of the incline and the component of F hand perpendicular to the surface of the incline is equal and opposite to the normal force, but it is not a action-reaction pair ; e.g. , two forces equal and opposite to each other. 003 10.0 points A push or pull that gives energy to an ob- ject, causing that object to start moving, stop moving, or change its motion is 1. a force. correct 2. inertia. 3. pressure. 4. friction. Explanation: 004 (part 1 of 2) 10.0 points A dog pulls on a pillow with a force of 6 . 8 N at an angle of 22 above the horizontal a) What is the x component of this force?...
View Full Document