Answer:

Explanation:
for the unit vector, we need to divide the given vector by its norm, because it should be in the SAME direction as the original vector, but of magnitude "1".
We notice that the norm of the given vector is:

Then, the unit vector becomes:

Answer:
But there are ways to harness kinetic energy to either generate useful mechanical work or electricity. This is what many have tried to do to make use of energy that would be otherwise wasted. One way to harness kinetic energy that has popped up many times in recent years has to do with roads and speed bumps
Explanation:
Input = 2,150 J; Output = 750 J
The efficiency of the engine = Output / Input = 750 J / 2,15 J = 0.3488
Answer: 0.3488 or 34.88 %