Question

a spring when compressed by 4cm has 2J energy stored in it. the force required to extend it by 8cm will be​

Answer 1

Question :

A spring when compressed by 4cm has 2J energy stored in it.The force required to extend it by 8cm will be?

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Answer : 200 N

Explaination :

We know energy of a spring is given by $\bf\bold{\frac{1} {2}kx^2}$

By putting the values

$\bf\bold{2=\frac{1} {2}k(4)^2 \times\:10^{-4}}$

Further solving

We got k = 250

Now, we know

Force = kx ⇒F = 250 × 0.08 = 200 N

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Brainly Extra knowledge :

• Spring force is conservative force as work done by spring is path independent.
• It only depends on initial and final position.

Answer 2

Answer:

200 Newtons.

Explanation:

Given Data -

Compressed by 4cm.

Energy - 2 Joules.

To Find -

The force required to extend it by 8cm.

Solution -

As we know,

$\bigstar\;\boxed{\sf \dfrac{1} {2}kx^2}$

Values in Equation,

$\sf\\ \\\implies 2=\dfrac{1} {2}k(4)^2 \times\:10^{-4}\\ \\\implies k = 250$

As we know,

$\bigstar\;\boxed{\sf Force = kx}}$

So,

$\sf\\ \\\implies F = 250\times 0.08\\ \\\implies 200\;N$

∴ The force required to extend it by 8cm will be​ 200 N.