1. Physics

2. Newton’s Laws Newton’s First Law: The Law of Inertia. A body at rest and a body in motion continues to move at constant velocity unless acted upon by an unbalanced external force.

3. Newton’s Laws Newton’s Second Law: The Law of Acceleration. A net or unbalanced force acting on an object equals the mass of the object times the acceleration of that object.

4. Newton’s Laws For Centripetal acceleration:

5. Newton’s Laws Sample Problem: Find the acceleration of a 3 slug object acted upon by a net force of 1.5 lbs.

6. Newton’s Laws Sample Problem: A 50-kg block rests at the top of the plane whose length is 2.00 m and whose height is 0.50 m. How long will it take for the block to slide to the bottom of the plane when released?

7. Newton’s Laws Solution: Draw the vector diagram first.

8. Newton’s Laws Next establish the relationship:

9. Newton’s Laws

11. Newton’s Third Law: The Law of Interaction. No matter what the circumstance, when one object exerts a force, the second must exert an exactly equal and oppositely directed force on the first.

12. Newton’s Laws For propeller problems, it is given by the formula: where:

13. Newton’s Laws Sample Problem: Each second a propeller accelerates an air mass of 12.2 slugs from rest to a velocity of 137 ft/sec. How much thrust is provided?

14. Newton’s Laws Solution:

15. Exercises 1.Find the net force on a 5 slug object which is accelerating at 3 ft/sec? 2.At an altitude of 10,665 m and a cruising speed of 252m/sec, the Pratt & Whitney JT 9D-7F in the Boeing 747 has a mass flow of 879 kg/sec and an exhaust velocity of 306 m/sec. Find the thrust. 3.A 60 lb block rests on a smooth plane inclined at an angle of 20˚ with the horizontal. The block is pulled up the plane with a force of 30 lb parallel to the plane. What is its acceleration?