Question

A horizontal force F pulls a 20.0 kg carton across the floor at constant speed. If the coefficient of sliding friction (fk) between carton and floor is 0.60, how much work does F do in moving the carton 3.00 m ?

Answer 1

Since the box is moved at a constant velocity,the applied force F just overcomes the frictional force f,i.e,

F=f=μmg

∴ Work done

W=FScosθ

W=μmgScos0∘

W=(0.6)(20)(10)(3)(1)

W=360 J

Answer 2

Answer:

352.8 J      (aprox.=353 J)

Explanation:

Since the box is moved at a constant velocity,the applied force F just overcomes the frictional force f,i.e,

F=f=μmg

∴ Work done

W=FS

W=(0.6)(20)(9.8)(3)

W=352.8 J

(aprox 353 J)