Assuming a typical efficiency for energy use by the body, how many slices of pizza must you eat to walk for 3.0h at a speed of 5.0 km/h? assume that your mass is 68 kg, metabolic power of 68 kg individual walking at 5 km/h is 380 w , and the energy content of slice of pizza is 1260 kj. number of slices of pizza=

n = 3.26

Explanation:

given,

human need 380 W of power to walking 5 Km/hr

human body 380 J of energy per second for walking 5 Km/h

speed of human 5 x 0.278 = 1.39 m/s  

for walking 1.39 m energy required = 380 J

distance traveled in 3 hours of walking

d = 1.39 x 3 x 3600

d = 15012 m

energy needed

E = 4,104,000 J

now,

one pizza slice give 1260000 J pf energy

slice of pizza

n = 3.26

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.