An example you could use for this would be if you threw a pencil across the room 10m away. the pencil would have travelled 10m(N). you could determine the objects speed by using the formula speed=distance/time. you would have had to time how long it took for the pencil to hit the 10m marking and divide 10 by however many seconds it took.
Energy at top = U = mgh = 40 * 9.8 * 12 = 4704 J
Energy at bottom = 1/2 mv² = 1/2 * 40 * 10² = 4000 / 2 = 2000 J
Energy Lost = Final - Initial = 4704 - 2000 = 2704 J
In short, Your Answer would be 2704 Joules
Hope this helps!
When light passes from one medium to another, part of it continues on
into the new medium, while the rest of it bounces away from the boundary,
back into the first medium.
The part of the light that continues on into the new medium is <em>transmitted</em>
light. Its forward progress at any point in its journey is <em>transmission</em>.
Its direction usually changes as it crosses the boundary. The bending is <em>
refraction</em>.
The part of the light that bounces away from the boundary and heads back
into the first medium is <em>reflected</em> light. The process of bouncing is <em>reflection</em>.
W=F*S
W - Work
F - Force
S - Distance (from latin word 'spatium)
so...
S= 5 (m)
W=60 (J)
W=F*S
F=W/S
F=60/5=12 J/m = 12 N (Newtons)
This is a problem that would be a good test of your understanding rather than your ability to work the formulas. 5m/s² means that the velocity increase each second is 5 m/s. So 4 s of that acceleration would increase the speed (in m/s) from 20 to 40. (Speed increase each second is 5 m/s. We need an increase of 20 m/s.)
Since the acceleration is uniform during those 4 s, we can use the simple average speed of 30 m/s. 30 m/s * 4 s = 120 m.