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Suppose that 2 J of work is needed to stretch a spring from its natural length of 30 cm to a length of 42 cm. (a) How much work is needed to stretch the spring from 35 cm to 40 cm? (b) How far beyond its natural length will a force of 30 N keep the spring stretched?

Respuesta :

Answer:

(a) 1.042 J

b) 0.108 m

Explanation:

(a)

W = work done to stretch the spring = 2 J

k = spring constant

L₀ = initial length = 30 cm = 0.30 m

L = final length = 42 cm = 0.42 m

x = stretch of the spring = L - L₀ = 0.42 - 0.30 = 0.12 m

Work done to stretch the spring is given as

W = (0.5) k x²

2 = (0.5) k (0.12)²

k = 277.78 N/m

x₀ = initial stretch of the spring = 35 - 30 = 5 cm = 0.05 m

x = final stretch of the spring = 40 - 30 = 10 cm = 0.10 m

W' = work needed to stretch the spring from 35 cm to 40 cm

Work needed to stretch the spring from 35 cm to 40 cm is given as

W' = (0.5) k (x² - x₀²)

W' = (0.5) (277.78) (0.10² - 0.05²)

W' = 1.042 J

b)

x = Stretch of the spring beyond natural length

F = force = 30 N

Spring force is given as

F = k x

30 = (277.78) x

x = 0.108 m

(a) The work is needed to stretch the spring from 35 cm to 40 cm is 1.042 J.

(b) Beyond the length of 0.108 m  force of 30 N keep the spring stretched.

what is spring force?

In order to stretch or compress the spring some amount of work has to be done. Which is given as,

          [tex]\rm{W=\frac{1}{2} Kx^{2} }[/tex]  

where k = spring constant of the spring

          x = compression of spring

          W= Work required or spring work

Initial length is given by 30 cm = 0.30 m

final length is given by  42 cm = 0.42 m

When spring is stretched change in the length occurs denoted by x

x = final length - initial length =0.42 - 0.30 = 0.12 m

[tex]\rm{W=\frac{1}{2} Kx^{2} }[/tex]

[tex]\rm{2=\frac{1}{2} K(0.12)^{2} }[/tex]

K= 277.78 N/m

(a) work is needed to stretch the spring from 35 cm to 40 cm

stretching length from30cm to 35 is 5 cm which is 0.05 m

stretching length from cm to 30 is 40 cm is 10 cm which is 0.1m

x = final stretch of the spring = 40 - 30 = 10 cm = 0.10 m

Work needed to stretch the spring from 35 cm to 40 cm is given

W = (0.5)K([0.1]² - [0.5]²)

W = (0.5) (277.78) (0.10² - 0.05²)

W = 1.042 J

x is stretch of the spring beyond natural length

F = force = 30 N

Spring force is given as

F = k x

30 = (277.78) x

x = 0.108 m

To learn more about the spring work refer to the link

https://brainly.in/question/18110192

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