OpenStudy (anonymous):

Heya, anyone who's good at Dynamics. I have a question involving kinetic friction. There's a box weighing 12 lb moving at a velocity of 4 ft/s on the ground when force F = (8t^2) lb is applied. Coefficient of kinetic friction is 0.2. It wants me to find the velocity at time equals 2 seconds. I've gone through it a couple of times and my answer keeps coming up as v = 163 ft/s. This is apparently wrong though, and I'm running out of attempts. Can someone help me? I'd be more than happy to tell you my methodology for the answer I've got.

2 years ago
OpenStudy (anonymous):

Here's an illustration of te|dw:1444290768592:dw|

2 years ago
OpenStudy (anonymous):

The FBD I drew: |dw:1444290900790:dw| where N = normal force, W = weight, and f_k = kinetic friction

2 years ago