The SOPHia project owns their own beehive, which is fitted with sensors that can make measurements in real time. We can measure how heavy the hive gets over time, as the bees produce more and more honey. Using the data we get from the live feed, we can learn how a physicist makes observations and analyses data in their experiments. We will also explore how graphs can be used to learn more about a set of data.

Every day the bees leave the hive to collect food to make into honey, returning at night. The honey production increases over time until they have filled up their honey combs. Once they have done this, the beekeepers will add a ‘super’, which is a new box that they can fill with honey. The red line is the actual data recorded by the Beehive Monitor system. The black lines have been added to show the average. (Image credit: Vincent Casey)

In everyday speech we would talk about the weight of the beehive if we want to say how heavy it is. In physics the weight of the beehive means the pull of gravity on the beehive, while the mass of it is the amount of matter (here the amount of beehive, bees and honey!!) measured in kilograms or grams. For a better explanation of this, read about *Forces and Work*. The graph below shows the change in weight of a beehive over the course of 1200 hours (or 50 days). This is the total weight of the hive, which accounts for the bees plus the weight of the honey they produce.

Four points are shown on the graph: **A**, **B**, **C** and **D**. They show a change in the rate of weight gain (i.e. more honey
being produced) over the course of 50 days.

- At Point A, the hive was fitted with the monitoring system. The hive was opened a few times throughout the 50 days, we can see this as a spike in the weight every once in a while, we’ll leave these out of our analysis.
- At Point B, after 400 hours we finally see an increase in the weight of the hive, this indicates that honey is starting to be produced. We can see this by the increased slope of the black line between points B and C.
- At Point C a super was added and again on July
20
^{th}. This allowed for more honey to be produced, therefore the weight of the hive could increase. Again we see an increase in the rate of honey production between point C and D. - Point D is the end of the 50 days (1200 hours) that were monitored.

Using the graph below, please answer the following questions:

(Image credit: Vincent Casey)

**1)** The red line shows the weight of the hive oscillates up and down in a regular pattern. Notice this happens about once every day. What could be causing the hive to change in weight so frequently?

**2)** Work out how many days have passed since the hive was first fitted with the monitoring system at point B and at point C.

**3)** If the rate of honey production remains constant up to point D, what will be the total change in the weight of the hive over the course of 1200 hours (From A to D)?

**4)** What is the slope of the average line from B to C? (Hint: to find the slope of a line you get the rise/run)

**5)** What is the slope of the average line from C to D? What does
the difference in the slope tell us about what is happening? Why is this
happening?

**6) **If the rate of honey production remained constant after point D, what will the weight of the hive be at 1400 hours?