Question

it is given that the increase in length of an elastic spring varies directly as the mass hung from it if 50 kg produces an increase of 2.5 cm then how many kg would produce an increase of 7.5 cm

Answer 1

Answer:

150kg

Step-by-step explanation:

for spring Mg=Kx

$\frac{m}{x} = constant$

or 50/2.5=M/7.5

M=50×3=150kg

Answer 2

Answer:

M = 150 Kg

Step-by-step explanation:

Let L denote the change in the length of the spring and M denote the mass of body which is hang to spring then

According to physical situation

  L is directly proportional to M

         That is

            L ∝ M

Then

     L = kM   where K is the constant which depends on material of spring

Now if L = 2.5 and M = 50 kg then

    2.5 = K (50)

⇒     K = (2.5/50)

NOW

if the L is 7.5 then value of M can be find out as

        L = K (M)

Putting the values of L and K we get

       M = 7.5(50/2.5) = 150 Kg

Thus

       M = 150 Kg

So we can produce the length of 7.5 by hanging by 150 Kg