1LA box is pulled 6 meters across the ground at a constant velocity by a horizon

Question

1LA box is pulled 6 meters across the ground at a constant velocity by a horizontally applied force of 50 newtons, At the same time, kinetic friction acts on the box as it slides so that it eventually stops when the pulling force stops. What is the magnitude of the frictional force? How much work does the frictional force do? What is the petwork done on the box? 2) In our Work-Energy experiment, why do we have to change the Logger-Pro Force graph from a Force vs. Time graph to a Force vs. Position graph? 3) What is the S.l. unit for work? How is it defined? 4) In our Work-Energy experiment, if we use a 100 gram hanging mass that falls through 1.5 meters, what will the kinetic energy of the cart be?

Explanation / Answer

A. Since when pulling force is removed(stops acting) motion also stops that means to move with constant velocity pulling force must be balancing friction .

thus

friction + pulling force =0

so

friction force =-50 newton

(negative sign only indicates that direction is opposite)

WorkDone by friction force = (friction force × displacement)=(-50×6)J= -300joule

network done = K = (final kinetic energy )-(initial kinetic.energy )=0 joule

(since velocity is constant so kinetic energy is also constant thus K=0 )

2.

area of Force vs time graph gives the value of change in momentum

area of force vs displacement graph gives change in kinetic energy (or work done by force)

3.SI unit of work is Joule .

4.kinetic.energy K= mgh= (0.1×9.8×1.5)=1.47J

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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