Two horses pull a large crate of negligible mass at constant speed across a barn

Question

Two horses pull a large crate of negligible mass at constant speed across a barn floor by means of two light steel cables. A large box of mass 230 kg sits on the crate (see the figure below, which shows a top-down view of the crate and box). As the horses pull, the cables are parallel to the horizontal floor. The coefficient of friction between the crate and the barn floor is 0.25.
(a) What is the work done by each horse if the box is moved a distance of 23 m?
(b) What is the tension in each cable if the angle between each and the direction the crate moves is 15°?

Explanation / Answer

    the mass of the large box(m)= 230 kg

the coefficient of friction between the crate and barn floor(u)=0.25

                                                         distance moved(d)=23 m

(a) the work done by the each horse can be calculted by

                   work done(W)= force (F). distance moved(d)

   in order to move the crate , the horses must be applied an amount of force is equal to weight of the crate and to over come the frictional force.

thus, the force(F)   = u (mg)

   wher mg is the weight of the crate and u is the coefficient of friction

      on sub. the values F= 0.25(230)(9.8)

                                    =563.5 N

        hence ,the workdone by the horse on the crate to move a distance 23m

                                       W=F. d   

                                          =563.5(23)

                                          =12960 J

(b)        the tension in the each cable at an angle 15

             the tension(T)= F cos 15

                                  = 544.2 N                               

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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