Question

A collie drags its bed box across a floor by applying a horizontal force of 6.5 N. The kinetic frictional force acting on the box has magnitude 1.8 N. As the box is dragged through 0.84 m along the way, what are (a) the work done by the collie's applied force and (b) the increase in thermal energy of the bed and floor?

Answer 1

(a) 5.46 J

(b) 1.51 J

Step-by-step explanation:

Work done=Force* Distance

(a)

Work done= Applied horizontal force * Distance

Substituting distance with 0.84m, Force by 6.5N

Work done=6.5*0.84=5.46 Nm or J

(b)

Increase in thermal energy of the bed and floor

The increase in energy is caused by frictional force whose value is provided as 1.8 N

Therefore, energy=Force*distance

Using distance of 0.84m and force of 1.8N

Energy=1.8*0.84=1.512 Nm or J