A 500-N box is pushed across a horizontal floor with a force of 250 N. The coefficient of kinetic friction is 0.4 Find the work done in pushing the box 20 m. How much work went into overcoming friction and how much into accelerating the box?

Explanation:

W = Fd

work input to the box

W = 250(20) = 5000 J

work of friction

Wf = μ(mg)d = 0.4(500)(-20) = -4000 J

Kinetic energy change (accelerating the box)

5000 - 4000 = 1000 J

260 miles per hour

explanation:

  the unit of the measure =

explanation:

  the property that is quantified by the energy needed per of material to raise the temperature by one.

  si unit of energy = joule (j)

  si unit of temperature = kelvin (k)

  si unit of mass of material = kilogram (kg)

the property that is quantified by the energy needed per of material to raise the temperature by one is called specific heat.

the unit of specific heat is