# Help with finding the K value?

I shot a 50g mass from a makeshift slingshot. I need to find the K value for a project and I am completely lost. I have several trials so here are their datas i collected:

Trial 1-Distance of shot : 44.5m

Time in air : 2.6s

Initial Velocity : 1m=5.2s

Projectile mass : 50g

TRIAL 2

Distance of shot : 59.5m

Time in air : 3.6s

Initial Velocity : 1m=5.2s

Projectile mass : 50g

TRIAL 3

Distance of shot : 42.8m

Time in air : 3.1s

Initial Velocity : 1m=5.2s

Projectile mass : 50g

TRIAL 4

Distance of shot : 54.5m

Time in air : 3.0s

Initial Velocity : 1m=5.2s

Projectile mass : 50g

I do not expect you to answer it for me, but a little help and steps of how to find it would be really appreciated, Thank you.

Say Trial 1's pull back is 1.3, Trial 2 is 1.7 trial 3 is 1.7 and trial 4 is 1.8m

### 1 Answer

- 7 years agoBest Answer
I assume that you want to find the spring constant, k from hooks law. F = kx meaning that there is a linear relationship between the force of a spring and how far stretched it is. You cannot find k with the data that you have because you do not know x. You need to mesure the force at different x distances.