1. Work

2. Work – is a quantity that exist whenever a force acting upon an object causes a displacement. Displacement – a vector quantity, which refers to “how much an object has covered” during its motion.

3. Work In order for a force to qualify as having work done on an object, there must be a displacement and the force must cause the displacement. 1 Joule = 1 Newton x 1 meter

4. Work or No Work? There are several good examples of work that can be observed in everyday life. For example: (Displacement) A horse pulling a wagon. A weightlifter lifting a barbell above his head. A freshman lifting a backpack full of books upon his shoulder.

5. How to Compute work done on an object? For example, A man pushes a Crate with a force of 10 N at the distance of 2 meters. How much work is done? Formula: W = F (Force) x D (Distance)

6. How to Compute work done on an object? Using the formula, Just substitute the force applied and the distance traveled. F = 10 N D = 2 m W = F x D = 10 N x 2 m = 20 Joules

7. Work done against gravity The work needed to lift an object of mass m against gravity is easy to figure out. The force of gravity on the object is simply its weight w = mg. That will be our F. What will be out displacement? It is just simply the height to which the object is raised. Thus: W = F x d = mg x h

8. How to Compute work done Work done against gravity? Eating a banana enables a person to perform about 4.0 x 10^4 J of work. How high can a 60 kg woman climb if energized by eating a banana? Given: W = 4.0 x 10^4 J m = 60 kg

9. How to Compute work done Work done against gravity? Since the motion is along the vertical, we can use the equation for work done against gravity, then solve for h From W = mgh We will use h = W mg

10. How to Compute work done Work done against gravity? h = W = 4 x 10^4 J mg 60 kg (9.8 m/s^2) = 4 x 10^4 kg – m^2/s^2 588 kg – m^2/s^2 = 68 m