The chandelier in my house has about 339 J of potential energy. if it is 3 meters off the ground, what is the mass of the chandelier?

1 answer

To find the mass of the chandelier, we can use the formula for gravitational potential energy (PE):

\[ PE = mgh \]

where:

  • \( PE \) is the potential energy (in joules),
  • \( m \) is the mass (in kilograms),
  • \( g \) is the acceleration due to gravity (approximately \( 9.81 , \text{m/s}^2 \)),
  • \( h \) is the height (in meters).

We know that:

  • \( PE = 339 , \text{J} \)
  • \( h = 3 , \text{m} \)
  • \( g = 9.81 , \text{m/s}^2 \)

We can rearrange the equation to solve for \( m \):

\[ m = \frac{PE}{gh} \]

Now we can substitute in the known values:

\[ m = \frac{339 , \text{J}}{(9.81 , \text{m/s}^2)(3 , \text{m})} \]

Calculating the denominator:

\[ 9.81 , \text{m/s}^2 \times 3 , \text{m} = 29.43 , \text{m}^2/\text{s}^2 \]

Now, substitute this result back into the equation for \( m \):

\[ m = \frac{339 , \text{J}}{29.43 , \text{m}^2/\text{s}^2} \approx 11.52 , \text{kg} \]

So, the mass of the chandelier is approximately 11.52 kg.