The effiency of a machine is
(output work or energy) / (input work or energy) .
For the system described in the question, that's
(123 J) / (150 J) = 0.82 = 82% .
It depends on your definition of “ancient.” Radiometric dating using Carbon-14 can reliably date back to about 50,000 years, uranium-lead or lead-lead dating can date back multiple millions, potassium-argon dating can reach 1.5 billion, and rubidium-strontium can reach 50 billion (nearly 4x the age of the universe). It depends on the context in which this question is being asked.
<span>The correct answer is B. Inverted image. This is because of all the lenses and light refractions and what not. The same things happens with our eyes except our brains fix the inverted image automatically. Since there are no brains in a projector, you have to fix it on your own by putting it in reverse.</span>
ANSWER: 1.6N (forth option)
EXPLANATION:
E= Force x displacement
69=F(42)
69/42 = F
F=1.64 N
Answer : 1.6N
Static electricity travels to the door knob because of the friction caused by the feet on the carpet. the friction traveled through the person, to their hand, and to the door knob because it is the best conductor.
