To determine the outcome of using a 700-gram car instead of a 500-gram car at point X on a wooden racetrack, we need to consider how mass affects potential and kinetic energy.
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Potential Energy (PE): The potential energy at a height is given by the formula: \[ PE = m \cdot g \cdot h \] where \( m \) is the mass, \( g \) is the acceleration due to gravity, and \( h \) is the height. If the height remains the same, a 700-gram car (0.7 kg) will have more potential energy than a 500-gram car (0.5 kg) because potential energy is directly proportional to mass.
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Kinetic Energy (KE): The kinetic energy at the bottom of the track will be derived from the potential energy at the top, assuming no energy losses. The kinetic energy is calculated using the formula: \[ KE = \frac{1}{2} m v^2 \] As the 700-gram car starts from the same height, it will have converted all its potential energy to kinetic energy at the bottom of the racetrack, and it will have more KE than the 500-gram car due to its greater mass (and thus greater initial potential energy).
From this analysis:
- The 700-gram car will have more potential energy at point X (since it is heavier).
- It will also have more kinetic energy at the bottom of the racetrack (since it converts that potential energy to kinetic energy).
Therefore, the correct response is:
A 700-gram car would have more potential energy at point X and more kinetic energy at the bottom of the racetrack.