Answer:
The vector equation of the line is

Parametric equations for given line are

Explanation:
The vector equation of the line is given by

r₀ = (7, -8, 3)
v = (1, 6, -13)
At these points the vector equation for this line is:

Parametric equations for given line are

Answer:
The pressure of liquid column is given by p=hpg, where h is depth, p is density and g is acceleration due to gravity.
Therefore, pressure of the liquid column increases with depth. The height of the blood column in a human body is more at feet than at the brain. Therefore, the blood pressure in humans is greater at the feet than the brain.
Answer:
it floats because the lake is cold at that moment so when part of the lake freezes it still remains solid and floats because of the lake and the surrounding of the lake is still cold
(a) Let
be the maximum linear speed with which the ball can move in a circle without breaking the cord. Its centripetal/radial acceleration has magnitude

where
is the radius of the circle.
The tension in the cord is what makes the ball move in its plane. By Newton's second law, the maximum net force on it is

so that

Solve for
:

(b) The net force equation in part (a) leads us to the relation

so that
is directly proportional to the square root of
. As the radius
increases, the maximum linear speed
will also increase, so the cord is less likely to break if we keep up the same speed.