Eric is swimming along the surface of the sea. He uses positive numbers to represent elevations above the surface of the sea and negative numbers to represent depths under the surface of the sea. Mark is sitting on the deck of a ship above Eric , and Ariel is diving beneath Eric. Who could be at an elevation of -3 m?

Ariel will be at an elevation of -3 m.

Step-by-step explanation:

There are three persons Eric, Mark and Ariel.

Location of these persons are,

Mark - Sitting at deck (Above the sea level)

Eric - swimming along the surface (At the sea level)

Ariel - diving beneath Eric (Below the sea level)

Since, all the distances above the sea level are measured with positive notation and below the sea level with negative.

Ariel will be at an elevation of -3 m.

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12

i dony know

step-by-step explanation: