backing tire?

head tire!

What is the flame depth $($in meters$)$ of the

What is the flame length $($in meters$)$ of the

a$.$

$(4$ pts$)$ For this conceptual model, indicate whether each arrow $($a$-$d$)$ represents a

$($positive$)$ or $-($negative$)$ relationship. Please answer on each line with $a+r_{-}$

b$.$

c$.$

d$.$