Final answer:
The experiment of clapping and recording the time heard echo is a bad experiment because it does not control all the variables and does not generate a consistent sound. To conduct a more reliable experiment, precise measurements and controlled sound sources should be used.
Step-by-step explanation:
The experiment of clapping and recording the time heard echo is a bad experiment because it does not control all the variables. For example, the distance between the cliffs, the angle of the cliffs, and the surrounding environment can all affect the time it takes for the echo to reach the person recording the time. Additionally, the method of clapping hands might not generate a consistent sound that can be accurately measured. To conduct a more reliable experiment, the distance between the cliffs should be measured precisely, a controlled sound source like a whistle should be used, and the experiment should be repeated multiple times to obtain accurate results.