An object slides down an incline with a frictionless surface a) Net work done on

Question

An object slides down an incline with a frictionless surface

a) Net work done on the object is zero

b) Net work done on the object is larger than 0 (that it’s positive)

c) Net work done on the object is smaller than zero (that it’s negative)

d) Net work may be positive or negative depending of chosen positive direction

There’s only one option which can be marked

My thoughts: the component of gravity force parallel to the surface will make the object slides down. So the gravity will do work for sure. So I am thinking that b) is the correct answer if I define down the positive direction. However, If I define up to be positive direction however, the work will be negative

I feel this is a trick question and that d) is the correct answer here. I am not certain

Explanation / Answer

Here, Net work done on the object = F * s * cos(theta)

where, F = force acting on object

           s = displacement

           (theta) = direction between F and s

Thus, Net work done on the object is greater than zero .

Thus, correct option is -

b) Net work done on the object is larger than 0 (that it’s positive) .

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.