# Vector box of mass problem

1. Dec 14, 2007

### quickclick330

1. The problem statement, all variables and given/known data

4. A box of mass M=10 kg is at rest on a frictionless level surface (like an ideally smooth
ice rink). A rope tied to the box is pulled horizontally, such that the tension in the rope is
(vector-->)T = 75 ˆx + 25 ˆz N, where both the x-axis and the z-axis are parallel to the floor. What is
the speed of the box after 0.05 seconds?
1. 0.395 m/s
2. 0.264 m/s
3. 0.198 m/s
4. 0.158 m/s
5. 0.132 m/s
6. 0.000 m/s

2. Relevant equations

pf = pi +Fnet*dt

3. The attempt at a solution

I know how to solve this problem, I'm just having trouble when it comes to the vectors in this case.

Pf = pi + Fnet*dt
{pi = 0) so..

Pf = Fnet*dt

p = mv

mvf = Fnet* dt

vf = (Fnet *dt)/m

2. Dec 14, 2007

### kudoushinichi88

I don't quite understand your notation... Can you explain them?

This question is quite fundamental... Since the force is given in vector form, you must first find the magnitude of the force. It should be clear where you should be heading to afterwards.

3. Dec 14, 2007

### quickclick330

Notation for which part?