# If the length of a #40 cm# spring increases to #64 cm# when a #7 kg# weight is hanging from it, what is the spring's constant?

##### 1 Answer

Dec 9, 2015

#### Answer:

#### Explanation:

you can simply apply the data into the equation

where

nevertheless, according to newton's third law, the inner force that occur inside the spring is equal to the force that is put to it from the outside. which is the weight of the object.

applying the data,