<u>Answer:</u>
Option A is the correct answer.
<u>Explanation:</u>
Let the east point towards positive X-axis and north point towards positive Y-axis.
First walking 1.2 km north, displacement = 1.2 j km
Secondly 1.6 km east, displacement = 1.6 i km
Total displacement = (1.6 i + 1.2 j) km
Magnitude = 
Angle of resultant with positive X - axis =
= 36.87⁰ east of north.
Answer:
b) true. The jobs are equal
Explanation:
The work on a body is the scalar product of the force applied by the distance traveled.
W = F. d
Work is a scalar, the work equation can be developed
W = F d cos θ
Where θ is the angle between force and displacement
Let's apply these conditions to the exercise
a) False, if we see the expression d cosT is the projection of the displacement in the direction of the force, so there may be several displacement, but its projection is always the same
b) true. The jobs are equal dx = d cosθ
c) False, because the force is equal and the projection of displacement is the same
d) False, knowledge of T is not necessary because the projection of displacement is always the same
e) False mass is not in the definition of work
Answer: C.
Explanation:
For a parallel-plate capacitor where the distance between the plates is d.
The capacitance is:
C = e*A/d
You can see that the distance is in the denominator, then if we double the distance, the capacitance halves.
Now, the stored energy can be written as:
E = (1/2)*Q^2/C
Now you can see that in this case, the capacitance is in the denominator, then we can rewrite this as:
E = (1/2)*Q^2*d/(e*A)
e is a constant, A is the area of the plates, that is also constant, and Q is the charge, that can not change because the capacitor is disconnected.
Then we can define:
K = (1/2)*Q^2/(e*A)
And now we can write the energy as:
E = K*d
Then the energy is proportional to the distance between the plates, this means that if we double the distance, we also double the energy.
Answer:
Refractive index of unknown liquid = 1.56
Explanation:
Using Snell's law as:
Where,
is the angle of incidence ( 65.0° )
is the angle of refraction ( 53.0° )
is the refractive index of the refraction medium (unknown liquid, n=?)
is the refractive index of the incidence medium (oil, n=1.38)
Hence,
Solving for
,
Refractive index of unknown liquid = 1.56