# physics

posted by
**daniel**
.

hello,

i have this question. Calculate the average force of friction acting on a wooden block as it propelled along the floor?

i have done the following solution

first of all i don't know what average force of friction means?

i found the Fapplied by strecthing the elastic 50 cm with a newton scale and found the force as 7N? but i don't this is the right way to do it. i then streched the elastic 50 cm and proppled in the ground.

i found the mass of the block with a balance beam.

my question is how do i go about doing this?

should i find velocity and proplled it a particular distance from point a to point b? should i find acceleration and then solve for force? please help me out thanks. i don't understand.

average force is the average over time.

The energy coming from the spring is 1/2 k x^2 where x is the amount the spring is stretched.

averageforcefriction*distanceslide is the work done on friction. Measure the sliding distance, and ADD the distance the spring was stretched ...

Set them equal, and calculate averageforcefriction