average force of friction

[hockey45]

hi guys,

i am having trouble with this problem.

Calculate the average force of friction acting on a wood block as it is propelled along the floor by an elastic band ?

 

my solution and my ideas:

What does it mean by average froce of friction?

I first weighed the peice of wood to find its mass. i then used a newton scale and pulled the elastic band 60 cm and found the force of friction which was 8n. is this force applied(8n)?did i measure the force correctly of the elastic.?i have no idea where to go from here. is there any kinetic energy involved? do i use Ek=1/2 mv^2. any suggestions would be helpful. do i time the wodeen block after i let it go and find the velocity. i am sure it is uniform acceleration.

thank you.

[Klaynos]

I don't think you will need to use Energy at all.

 

What you will need to do is remember that:

 

F_net=ma

 

And you know the mass and and you should be able to work out what F_net is in terms of friction and applied forces.

[hockey45]

please delete sorry