The Manga Guide to Physics

204 Chapter 4 Energy

Now, plugging in some real numbers for this, we know that 100 km/h equals the

following:

100

km

—

h

× 1000

m

—

km

×

1 h

—

3600 s

= 27.78

m

—

s

Now let’s put that value into our equation and see what we find:

h =

v

1

2

—

2g

h =

27.782

—

2 × 9.8 m/s

2

h = 39.36 m

The Orientation of Force and Work

As you know, we represent work in terms of force and the distance (or the displacement)

a force is applied to an object. Let’s consider an object being moved over displacement d,

undergoing a force F as shown below.

When the orientations of a force and displacement do not match, we must take this

into account. In the example above, work (W) is repr