Which change would cause the largest increase in a mountain climber’s gravitational potential energy?

carrying twice the weight and climbing half as high
carrying half the weight and climbing half as high
carrying twice the weight and climbing twice as high
carrying half the weight and climbing twice as high

1 answer

Gravitational potential energy (GPE) is given by the formula:

\[ \text{GPE} = mgh \]

where:

  • \( m \) is the mass (weight) of the object,
  • \( g \) is the acceleration due to gravity, and
  • \( h \) is the height climbed.

Now let's analyze the four options by calculating their potential energy changes.

  1. Carrying twice the weight and climbing half as high: \[ \text{GPE} = 2m \cdot g \cdot \frac{h}{2} = mg \cdot h \]

  2. Carrying half the weight and climbing half as high: \[ \text{GPE} = \frac{m}{2} \cdot g \cdot \frac{h}{2} = \frac{mg \cdot h}{4} \]

  3. Carrying twice the weight and climbing twice as high: \[ \text{GPE} = 2m \cdot g \cdot 2h = 4mg \cdot h \]

  4. Carrying half the weight and climbing twice as high: \[ \text{GPE} = \frac{m}{2} \cdot g \cdot 2h = mg \cdot h \]

Now compare the results:

  • Option 1: \( mg \cdot h \)
  • Option 2: \( \frac{mg \cdot h}{4} \)
  • Option 3: \( 4mg \cdot h \)
  • Option 4: \( mg \cdot h \)

The largest increase in gravitational potential energy comes from Option 3: carrying twice the weight and climbing twice as high, resulting in an increase of \( 4mg \cdot h \).