English

Science - Balanced and Unbalanced forces

We have had a fun-filled term learning about the forces all around us, in the first instance learning that pushes and pulls are examples of such, and that forces are needed to start and stop things and to change their speed and/or direction. We used practical investigations to illustrate these points, setting up a seesaw using a ruler as the lever and a glue stick as the fulcrum. A ball of paper was placed on one end of the ruler, the other end was struck with a fist and the paper flew into the air – we noted the downward force, the upward force (push) and the force of gravity which brought the ball of paper back to the ground. Working in pairs, one member of the team used the force exerted by their hand to change the direction of the ball of paper. We had a lot of tidying up to do afterwards! In our next experiment, we investigated the effect friction has on moving objects. We placed a shoe box on a table and lifted the legs at one end, measuring how far they were lifted from the ground before the box started to slide. We then repeated the procedure, each time placing different amounts of weight in the box. We agreed that the force of gravity made the box slide down the slope, but that friction between the box and the table top slowed it down. We learnt that mass refers to the amount of matter an object contains and that weight is a force caused by gravity. Mass never changes, but weight varies on different planets in accordance with the pull of gravity - we calculated our weight on Mercury, Mars, Saturn and other planets in our solar system. We put our computing skills to the test and presented this information in a table inserted into a Word document. Turning our attention to air resistance, small groups of children were challenged to drop a fresh egg from a height, and ensure it landed safely without breaking. They were given, a sheet of plastic, 2m of string, 1m of sellotape, three sheets of newspaper, one sheet of paper and one paper towel. There were some ingenious designs, and a couple of the eggs were unscathed upon landing! Using catapult boards, the children conducted an investigation to establish whether the amount of force applied to the elastic band was relative to the distance the Logo brick travelled when the band was released. Results were gathered, recorded in a table and a graph produced using excel. We have all thoroughly enjoyed our science topic and look forward to the challenges and new learning next term will bring!