<span>The line that is drawn perpendicular to the point at which a wave intersects a boundary is know as the Normal .
When the normal is drawn, the incident ray makes an angle with it known as the angle of incidence and the reflected ray makes an angle with it known as the angle of incidence. These angles are always equal.
The refracted ray makes an angle with the normal known as angle of refraction. The sin of angle of incidence to the sin of angle of refraction is called the refractive index( </span>μ= <span>sin i / sin r) .
hope all of it helps you!</span>
A pair of equal gravitational forces ... one in each direction ...
exists between every speck of mass in the universe and every
other speck of mass.
Answer:

Explanation:
As we know that resistance of one copper wire is given as

here we know that

now we have


now we know that such 17 resistors are connected in parallel so we have


Now if a single copper wire has same resistance then its diameter is D and it is given as

now from above two equations we have


now we have

Direction!
Velocity is a vector quantity and speed is a scalar quantity. Vector quantities includes both magnitude and direction, while scalar quantities only have magnitude. :)
Answer:
m v1 = (m + M) v2
v2 = m v1 / (m + M)
v2 = 7 * 74 / (74 + 65)
3.73 m/s
74 kg is too heavy for the cannonball (over 150 lbs)