Describing and experiment

First go through the list of materials needed to construct a potato gun. Read the steps. Then read the experiment description and results. Answer the questions in the Experiment quiz.
In the “Potato Gun” experiment, different verb tenses were used. Study the table below to make sure you understand their use.

Note

We use imperative to describe the method /steps (i.e. How the experiment should be carried out.).

1. Place the block on the table.

To describe the experiment itself (its demonstration) we use the present simple tense (active or passive) and future tense - will (i.e. We say what will happen.). We also use when/if …, it will …

When / If you push the potato, the volume of air will decrease. or When you push the potato, the volume of air decreases

To state the recent results of the experiment we use the present perfect tense (i.e. We state what has happened recently.). Not sure if this is very common -usually it’s stated as a present simple fact.

The increase of the air pressure has shot out the potato at the far end.

The increase of the air pressure shoots the potato out at the far end.

To report on the procedure and results of experiments, we use the past simple tense (active or passive). Both ends of the metal tube were plugged with potatoes.


Then go to the “Grammar quiz” and complete the sentences with the correct form of the verbs in brackets.
Finally go to the “Rocket experiment forum”. Study the instructions for the rocket experiment. This experiment is based on Newton’s third law. After studying the instructions, describe the experiment as if you were demonstrating it. Upload you suggestion to the forum.