Calculating Force Needed to Move a System of Bodies at 30 ft/s

[the_d]

My problem is to find the force needed to give the system of bodies a velocity of 30 ft/s after moving 20 ft. from rest.

Can anyone help me with this? All i have done is found EFx and EFy for the 50lb. force.

 

[radou]

Can't see the attachment though, but try to use the fact that the work done by that unknown force equals the change of kinetic energy. I hope this helps.

 

[the_d]

so the work equals 0.2? r u sure

 

[radou]

so the work equals 0.2? r u sure

No, I'm not sure until I see the diagram.

 

[the_d]

this is thr diagram

 

[radou]

this is thr diagram

I can't see it again - perhaps there's a problem with my computer, so someone other will be able to reply.

 

[the_d]

ok. thankx for you help thou

 

[the_d]

can someone help me with this problem