# Finding Tension in rope

1. Nov 25, 2013

### PerSempre

1. The problem statement, all variables and given/known data
The block moves at 2.3 m/s to the left (on a flat, horizontal surface). If μk, the coefficient of friction between the block and the floor, is .40, what is the tension in the rope? Also, the weight of the block is 9.8 N

2. Relevant equations

No equations were given... but I used Fk=μkFn

3. The attempt at a solution
2.3=.40Fn
Fn=5.75?
I googled how to find tension.. Some told me I needed three components: Ff, Fn, and Fg and some gave an acceleration for gravity. I don't understand how to go about this problem :/

2. Nov 25, 2013

### Staff: Mentor

What rope? Is there a rope pulling this block? Is the speed constant? What does that tell you?

You'll need that to figure out the friction force.

You set a speed (2.3 m/s) equal to a force. That makes no sense! :yuck: Also, Fn is given! No need to calculate it.

Start by drawing a free body diagram of the block. What forces act? What's the net force on the block?