A park has a 3m tall tetherball pole, and a 6.8m tall flagpole. The lengths of their shadows are proportional to their heights.

Complete question is;

A park has a 3 meter tall tether ball pole and a 6.8 m tall flagpole. The lengths of their shadows are proportional to their heights.

Which of the following could be the lengths of the shadows?

Choose 2 answers from the options attached.

Options B & D

Step-by-step explanation:

From the question, the proportional relationship between the height and shadow length is a direct proportionality. This means that an increase in the height, leads to an increase in the length of shadow and vice versa. Thus, the height to shadow length ratio is a constant.

Now, if we use x and y to denote length of shadow of tether ball pole and length of flagpole receptively, we will have;

3/x = 6.8/y

Let's make y the subject.

y = 6.8x/3

Looking at the options;

Option A: When x = 1.35 m, we have;

y = (6.8 × 1.35)/3 = 3.06 m

For Option B:

When x = 1.8 m,

y= (6.8 × 1.8)/3 = 4.08 m

For Option C:

When x= 3.75 m,

y = (6.8 × 3.75)/3 = 8.5 m

For option D:

When x = 0.6

y = (6.8 × 0.6)/3 = 1.36 m

For option E;

When x = 2,

y = (6.8 × 2)/3 = 4.533 m

From our calculations, the only values of y that correspond with the given value of y in the options are Options B & D

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

deez nu tz

step-by-step explanation: