The temperature started at 82° and continued to rise at a rate of 0.6° each hour the temperature is now 85° determine the number of hours, h, it took to reach 85°

5 hours

Step-by-step explanation:

Our goal here is 3 F because 82+3=85

Ok so you start at 82. For example, you can do 0.6×1=0.6 (no)

0.6×2=1.2 (no)

0.6×3=1.8 (no)

0.6×4=2.4 (no)

0.6×5=3 (yes)

82°+3°=85°

true? is that what you're asking or do you mean something else?

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