Question

A student slides her 80.0-kg desk across the level floor of her dormitory room a distance 4.00 m at constant speed. If the coefficient of kinetic friction between the desk and the floor is 0.400, how much work did she do

Answer 1

Work done is equal to 125.44 J

Step-by-step explanation:

We have given mass of the student m = 80 kg

Distance moved d = 4 m

Acceleration due to gravity
`g=9.8m/sec^2`

Coefficient of kinetic friction
`\mu =0.4`

So normal force exerted by student
`F=\mu mg=0.4* 80* 9.8=313.6N`

We know that work done is equal to multiplication of force and distance

So work done
`W=Fd=313.6* 0.4=125.44J`