Task 11

Materials and tools for a working group:

sling-shot, polystyrene ball, tool from previous task, ruler

While in the previous three tasks, pupils examined how distance of the impact of an object on the ground influences the direction of its firing, in this task, pupils will change the force of the object and observe what effect it will have on the impact distance of the object. First, the teacher discusses with the pupils what they have already found out, how to throw (which direction) the ball to get as far as possible. Pupils should refer to data obtained from previous tasks and indicate in which direction the ball should be thrown. Teacher asks pupils if they could ensure different way that the ball will fly further. Pupils can suggest different ways and the teacher discusses them. Then they focus on the fact that it is possible to increase the force exerted on the object being fired. He suggests that they try to stretch the sling rubber to different lengths and see how it affects the object‘s impact. However, it is important to ensure that they always shoot the ball in the same direction, either horizontally or at an angle of the same magnitude measured by a simple gauge from a previous task. The aim of the task is for pupils to get results in the form of numbers and to learn to draw results from the measured values.

Pupils carry out 4 measurements with differently stretched rubber on the sling. They always measure the length of the stroke (the length of the rubber when the slingshot is stretched) and what distance the object has flown. For ease of investigation, it is advisable to have a slingshot firmly fixed, for example in the ground. It is easier to control the firing angle, which must always be the same (which the teacher constantly points out to measure the pupils), as in the previous taskpupils have found that the distance of the object‘s impact depends on how obliquely we shoot the object. 

When making measurements, it is advisable to go from the smallest stretch of the sling to the largest, or vice versa, so that they can evaluate the results more easily. If the results in the table are scattered, it will be more difficult to formulate a general conclusion. The teacher will draw attention to this because it belongs to the development of the competence of scientific work within the systematization of data necessary for the creation of interpretive judgment.

From the data obtained, pupils conclude that they the distance the object will fly depends on force we use when firing it. It is very important that pupils justify their conclusions with measured data.