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Jessie and Jamie complete a 4.0km race. Each has a mass of 68kg. Jessie runs the race at 15km/hr; Jamie walks it at 5.0km/hr. Use the attached table to answer the following questions:

a. How much metabolic energy does Jessie use to complete the course?
b. How much metabolic energy does Jamie use to complete the course?

Jessie and Jamie complete a 40km race Each has a mass of 68kg Jessie runs the race at 15kmhr Jamie walks it at 50kmhr Use the attached table to answer the follo class=


Answer :

MathPhys

Answer:

a. 1.1 MJ

b. 1.1 MJ

Explanation:

The energy used (E) is equal to the power (P) times the time (t). The time it takes to complete the race is equal to the distance (d) divided by the speed (v).

a. The time it takes Jessie to complete the course is:

t = d / v

t = (4.0 km) / (15 km/hr)

t = 0.267 hr

t = 960 s

The energy used in that time is:

E = Pt

E = (1150 W) (960 s)

E = 1,104,000 J

Converting to megajoules and rounded to two significant figures:

E = 1.1 MJ

b The time it takes Jessie to complete the course is:

t = d / v

t = (4.0 km) / (5 km/hr)

t = 0.8 hr

t = 2880 s

The energy used in that time is:

E = Pt

E = (380 W) (2880 s)

E = 1,094,400 J

Converting to megajoules and rounded to two significant figures:

E = 1.1 MJ

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