Consider a system that consists of a single object, and consider a force F actin
ID: 2139573 • Letter: C
Question
Consider a system that consists of a single object, and consider a force F acting on that object. a) What must be true in order for us to say that "Force F does work on the system"? b) Just by looking at the motion of the system, can we tell if force F does positive or negative work? Explain. Consider a system that consists of a single object, and consider a force F acting on that object. a) What must be true in order for us to say that "Force F does work on the system"? b) Just by looking at the motion of the system, can we tell if force F does positive or negative work? Explain.Explanation / Answer
a) The object must be in aceleration ( i.e it should not go with a constant veocity) for force F applied on the object unless there there is another force appied on the object which is balancing this force F.
or in simple way you can say it should get displaced as W=F*s , s has to be nonzero for nonzero work.
b) Yes we can , we speed of the object is continuosly decreasing then force is in opposite direction of motion of the object (i.e negative) & if speed is continuosy increasing force is in the direction of motion (i.e positive)
now W=F*s
(taking direction of motion of positive)
positive force will do positive work and negative one will do negative work.