Respuesta :

Answer:

w = d×f = 2.1 × ( 5×9.8)= 102.9J

Explanation:

because the question is asking for the energy PE

Answer:

[tex]\boxed {\boxed {\sf 102.9 \ J}}[/tex]

Explanation:

Potential energy is the energy an object possesses due to position. The formula is:

[tex]PE= m \times g \times h[/tex]

where m is the mass, g is the acceleration due to gravity, and h is the height.

We know the book is 5 kilograms and is on a 2.1 meter high bookshelf. Since this is on Earth, the acceleration due to gravity is 9.8 meters per square second.

  • m= 5 kg
  • g= 9.8 m/s²
  • h= 2.1 m

Substitute the values into the formula.

[tex]PE= 5 \ kg \times 9.8 \ m/s^2 \times 2.1 \ m[/tex]

Multiply the numbers together.

[tex]PE= 49 kg *m/s^2 *2.1 \ m[/tex]

[tex]PE= 102.9 \ kg*m^2/s^2[/tex]

  • 1 kilogram square meter per square second ( 1 kg*m²/s²) is equal to 1 Joule (J).
  • So, our answ er of 102.9 kg*m²/s² is equal to 102.9 J

[tex]PE= 102.9 \ J[/tex]

The book has 102.9 Joules of gravitational potential energy.