contestada

Aril does 1800 J of work to get a canoe moving from rest. April and the canoe have a mass of 70 kg.

a. What is the kinetic energy of April and the canoe after she does the work?

b. What is their velocity after she does the work?

Respuesta :

a) KE=energy required to make them move=1800J

b) KE=1/2*mv^2, so [tex]v=\sqrt{\frac{2KE}{m}}=7.17[/tex] J

Answer:

a) KE = 1800 J

b) v = 7.17 m/s

Explanation:

Part a)

As we know by work energy theorem that work done by all force is always equal to change in kinetic energy of system

here we have

[tex]W = KE_f - KE_i[/tex]

given that

initial kinetic energy = 0

work done = 1800 J

so final kinetic energy will be

[tex]KE = 1800 J[/tex]

part b)

now we know that

[tex]KE = \frac{1}{2}mv^2[/tex]

now from above equation we have

[tex]1800 = \frac{1}{2}(70)v^2[/tex]

[tex]v^2 = \frac{1800}{35}[/tex]

now from above we have

[tex]v = 7.17 m/s[/tex]