A spring has a natural length of 12 cm. If a 28-N force is required to keep it stretched to a length of 18 cm, how much work W is required to stretch it from 12 cm to 15 cm

The Work required to stretch the spring W = 0.42 J

Explanation:

Natural length = 12 cm

Stretched length = 18 cm

Change in length ( x ) = 18 - 12 = 6 cm = 0.06 m

Force required = 28 N

We know that spring force F = k x --------- (1)

⇒ k =

⇒ k =

⇒ k = 466.67

This is the stiffness of the spring.

Now the force required to stretch the spring F = k

⇒ = change in length of spring = 15 - 12 = 3 cm = 0.03 m

⇒ F = 466.67 × 0.03

⇒ F = 14 N

Now the work required to stretch the spring W = F ×

⇒ W = 14 × 0.03

⇒ W = 0.42 J

This is the Work required to stretch the spring from 12 cm to 15 cm.

what type of charge does it have? negative

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.