A 10 kg box is being pulled by a force F = 85 N at an angle of 57degrees from the horizontal. Find the following quantities if the box is accelerated at 2.5 m/s2 for 14 m?
a. Work done by the external force
b. Work done by frictional force
c. Work done by net force

Question

A 10 kg box is being pulled by a force F = 85 N at an angle of 57degrees from the horizontal. Find the following quantities if the box is accelerated at 2.5 m/s2 for 14 m?
 a. Work done by the external force
b. Work done by frictional force
c. Work done by net force

anonymous · Answer

|dw:1403742513181:dw|

anonymous · Answer

Work Formula:
$$Work = Force \times Distance$$

anonymous · Answer

Hi! I understand how to do a
I just don't understand b and c

anonymous · Answer

Any help would be great!

abmon98 · Answer

Workdone by external force=Force*Distance
W=85*14=1190
Frictional Force is the Force Opposite to the force of movement 
R is the component of a force at right angles to the surface
R=10gcos(57)
External Force-(FrictionalForce+mgsin*angle)=m(mass)*a(acceleration)
85-(Ff+(10(g)*sin57)=10*2.5
85-(100*sin57)-ff=25

anonymous · Answer

Okay wow, thanks, how about the work done by the net force?

abmon98 · Answer

Your most welcome I think that net force is calculated using (external force-frictional force)