-- Looking at the dots casually, they look green because they absorb all other
colors of light, and only green light is left to proceed to your eyes. (In order for
this to work, there has to be some green in the light shining on the dots.
Daylight and most light bulbs work fine.)
-- The filter looks red because it absorbs all other colors of light, and only
the red light is left to pass through the filter and come out on the other side.
-- When the green light from the dots hits the red filter, it's absorbed in the
filter, and there's no light left to come out on the other side.
If you're looking through the filter at the dots, they look <em>black</em>.
If it produces 20J of light energy in a second, then that 20J is the 10% of the supply that becomes useful output.
20 J/s = 10% of Supply
20 J/s = (0.1) x (Supply)
Divide each side by 0.1:
Supply = (20 J/s) / (0.1)
<em>Supply = 200 J/s </em>(200 watts)
========================
Here's something to think about: What could you do to make the lamp more efficient ? Answer: Use it for a heater !
If you use it for a heater, then the HEAT is the 'useful' part, and the light is the part that you really don't care about. Suddenly ... bada-boom ... the lamp is 90% efficient !
Answer:
When you exert a force on a baseball, there exists an equal and opposite force on the ball therefore, the ball will accelerate in opposite direction.
Explanation:
When you hit a ball with baseball bat, the bat exerts a great force on the ball which causes the ball to accelerate in the opposite direction. It is to be noted that the mass of bat is much greater than mass of ball but the acceleration of ball is also greater than the acceleration of the bat so both bat and ball almost exert same magnitude of force but in opposite direction and as a result both bat and ball accelerate in opposite direction, the deciding factor is of course the relative force applied by the batter and the bowler.
Answer:F=648 N
Explanation:
Given
mass of man 
mass of Platform 
acceleration of system 
Let F be the force with which man pulls the rope which will also create a tension of F in rope
From Diagram
