Frequency would refer to the number of times that results would occur. This means that if you would like to measure how long it would take for the balls to bounce for a certain time, you would be able to get the frequency.
If you would like to know the relative frequency, this would refer to the times that it would take for the number of results to occur divided by the number of times that the experiment would have to be repeated. There are instances when the experiment would need to be repeated for a certain period of time for it to work. You just need to do simple division in order to solve relative frequency.