Answer:
The magnitude of vector B is 43 units and it points in the negative y-direction.
Explanation:
Resultant of vectors = vector sum of all the vectors
Vector A = 29j
Vector B = ?
Resultant of vector A and B = R = -14j
R = A + B
-14j = 29j + B
B = -14j - 29j = - 43j
Hence, the magnitude of vector B is 43 units and it points in the negative y-direction.
The heat capacity and the specific heat
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)
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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 !
About 10% to 15% of system charge
