Astudent skipped a step when she tried to convert 18 hours into seconds,
and she got the following incorrect result:
18 hours
60 seconds)
= 1080 seconds
1 minute
what conversion ratio did she skip in this multiple-step conversion?

The conversion of minutes to seconds is skipped in multiple-step conversion.

Step-by-step explanation:

Given:

To convert 18 hours into seconds.

Now, to get the conversion ratio skip in this multiple-step conversion.

First we need to convert hours into minutes:

1 hour = 60 minutes.

So, 18 hours =

                     = .

Then, we convert minutes into seconds:

1 minute = 60 seconds.

So, 1080 minutes =

                             =  .

Thus, 18 hours =  64800 seconds.

As given in question the conversion from hours to seconds is there but the conversion of minutes to second is not there it is skipped so the result is incorrect.

Therefore, the conversion of minutes to seconds is skipped in multiple-step conversion.

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