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A box of mass 3.6 kg is lifted 5.4 m above the
ground. What is the change in energy in lifting
the box to this height?


Sagot :

So, the energy change that occurs is 190.512 J.

Introduction

Hello ! I am Deva from Brainly Indonesia will help you regarding energy and its transformation. In this case, it's the use of energy from the lifter to be equivalent to the change in the object's potential energy. Why potential energy? Because the box undergoes a change in height and the potential energy specializes at a certain height. Work (W) due to change in potential energy ([tex] \sf{\Delta PE} [/tex]) can be realized in the equation :

[tex] \sf{W = \Delta PE} [/tex]

[tex] \sf{W = m \cdot g \cdot h_2 - m \cdot g \cdot h_2} [/tex]

[tex] \boxed{\sf{\bold{W = m \cdot g \cdot (h_2 - h_1)}}} [/tex]

With the following condition :

  • W = work of subject (J)
  • [tex] \sf{\Delta PE} [/tex] = change of potential energy (J)
  • m = mass (kg)
  • g = acceleration of the gravity (m/s²)
  • [tex] \sf{h_2} [/tex] = final height (m)
  • [tex] \sf{h_1} [/tex] = initial height (m)

Problem Solving

We know that :

  • m = mass = 3.6 kg
  • g = acceleration of the gravity = 9.8 m/s²
  • [tex] \sf{h_2} [/tex] = final height = 5.4 m
  • [tex] \sf{h_1} [/tex] = initial height = 0 m

What was asked :

  • W = work of subject = ... J

Step by step :

[tex] \sf{W = \Delta PE} [/tex]

[tex] \sf{W = m \cdot g \cdot (h_2 - h_1)} [/tex]

[tex] \sf{W = 3.6 \cdot 9.8 \cdot (5.4 - 0)} [/tex]

[tex] \sf{W = 3.6 \cdot 9.8 \cdot 5,4} [/tex]

[tex] \boxed{\sf{W = 190.512 \: J}} [/tex]

So, the energy change that occurs is 190.512 J.