Task 9

Materials and tools for a working group:

sling-shot, polystyrene ball, measuring tape

While in the task 8 pupils explored how to keep the ball as long as possible in the air, the ninth task is focused on exploring how to get the ball as far away from the point of firing as possible. Although at first glance it looks like it‘s the same research – the longer it gets in the air, the more it goes, it‘s not. An example is firing a ball upwards. Although the ball is relatively long in the air, it falls very close to where it was fired. Please note this.

The teacher asks pupils to make predictions. The situations are the same as in the previous task. It is relatively simple to assume the impact in the last two situations (C and D) – if we act on the ball in the direction of gravitational force or in the opposite direction. However, it is interesting to discuss with pupils whether it is necessary to shoot the ball more or less horizontally with the ground surface (perpendicular to the action of gravity) or obliquely upwards. In order to develop activities by developing the idea of causing movement of objects by multiple forces, it is advisable that the teacher discusses with the pupils in this way (i.e., recalls the effect of gravitational force and compares it to the direction of force when firing a ball from a sling). Pupils verify their predictions and formulate the result on the basis of the data obtained. Since the distance of the object‘s impact does not depend directly on the object‘s firing angle (see the figure below), it is advisable in this task to ensure that the pupils shoot the sling ball at a maximum angle of 45°. As shown in the diagram, if, for example, we shoot a sphere at 20° and 70° angle, the object falls on the same spot. To make the outcome of the ninth task clear for the pupils, it is appropriate if the pupils find that it is necessary to throw the object not perpendicular to the direction of gravitational force, but at a certain angle. Pupils can dedicate more to this examination in the following task.