Instructional Activities for teaching mass and weight for grade eight

             First you have to attract the audience attention by throwing a pen which will fall to the ground. Then after they recognized that earth gravity attracts all objects towards its center we model the earth by a magnet and pins and we change the distance between the pins and the magnet.

·         Does the pen have mass? Yes

·         Why does the pen fall down? Because of the effect of gravity that attracts objects.

·         What do we call this force of attraction? Weight

·         What conclusion can you draw regarding the experiment about magnet? That the magnet resembles the center of gravity and once we moved apart the gravity will decrease.

·         What will happen to the weight in such case? It will decrease too since the gravity decreased.

·         What is your weight on the moon? Our weight at the moon is negligible since the gravity is approximately zero.

·         Who can now give the definition of weight and what factors affect it? Weight is the force of gravity on a body. It is affected by altitude and position.

·         Now we talk about the story of an apple which was seen by Ishaa Newton.  Newton watched an apple falling on the ground. He started asking himself why the apple moved down. He started doing experiments to look at the reason behind this and at the end he discovered the law of gravity.

·         Who can differentiate now between mass and weight? Mass is the amount of matter found in a body whereas weight is the force of gravity on a body the mass is constant whereas the weight changes.

·         What is the relationship between mass and weight? Weight= mass X gravity

Students in this case should calculate their weight.