I can help you with that if you translate to English
Answer:
1 because I looked it up for sure
I think D. None of the above
I think that it
Answer:
(d) Negative.
Explanation:
let's test each at a time.
(a) It can't be 0, because cup would slide back other wise.
(b) Positive, well if forward is positive, than the work done against the forward acceleration must be negative , so it can't be positive.
(c) Equal to non-conservative work done by the car's engine.
well no, because work done by car's engine dosen't go all of it into getting car to move, so it can't be that.
(d) negative, this look like it, because work that friction does must be nagative to counteract positive thrust of car which is positive and in forward direction.
(d) this can't be true.
So the answer is (d) negative.
Answer:
Properties of semiconductors are determined by the energy gap between valence and conduction bands. To understand, what is semiconductor, we have to define these terms. In solid-state physics, the energy gap or the band gap is an energy range between valence band and conduction band where electron states are forbidden.
