Question

The gravitational potential energy of an object is defined as the energy it has due to its position in a gravitational field.
A ball with a weight of 50 N is lifted to a height of 1 meter. Which graph correctly represents the change in gravitational potential energy (shaded in blue) as it is lifted to this height?

On the pictures what should I be looking for??

Answer 1

To correctly identify the graph that represents the change in gravitational potential energy of the ball as it is lifted, you should look for the following features:

1. **Linear Relationship**: The gravitational potential energy (GPE) increases linearly with height in a uniform gravitational field. This means that as the height increases, the GPE should increase in a straight line.

2. **Formula for GPE**: The gravitational potential energy can be calculated using the formula:
\[
GPE = mgh
\]
Where:
- \( m \) is the mass of the object,
- \( g \) is the acceleration due to gravity (approximately 9.81 m/s² on Earth),
- \( h \) is the height above the reference point.
Since you have the weight (W) instead of mass, you can use:
\[
GPE = Wh
\]
Given that the ball has a weight of 50 N and is lifted to a height of 1 meter, the change in GPE would be:
\[
GPE = 50 \, \text{N} \times 1 \, \text{m} = 50 \, \text{Joules}
\]

3. **Axes**: Check if the x-axis of the graph is labelled with height (in meters) and the y-axis is labelled with potential energy (in Joules). The graph should show the GPE starting from zero at height zero and increasing as you go to 1 meter.

4. **Shading**: The section of the graph that represents the increase in gravitational potential energy from 0 to 1 meter should be shaded in blue.

In summary, the correct graph will show a straight line starting from the origin (0,0) and increasing up to (1, 50) with an appropriate range indicated on both axes.