P6 Science Forces QuizGecko PDF

Name : ____________________ Date : ____________________ TOPIC: FORCES P6 SCIENCE LEARNING OUTCOMES: 1. Identify a force as a push or a pull. 2. Understand the effects of a force. 3. Recognise the different types of forces; magnetic force gravitational force elastic spr...

Name : ____________________ Date : ____________________ TOPIC: FORCES P6 SCIENCE LEARNING OUTCOMES: 1. Identify a force as a push or a pull. 2. Understand the effects of a force. 3. Recognise the different types of forces; magnetic force gravitational force elastic spring force frictional force 4. Recognise that objects have weight because of the gravitational force between them and the Earth. WHAT IS A FORCE? 1. A force is a push or a pull. 2. A force cannot be seen but the effects can be felt or seen. 3. A force can: Move a stationary object. The force exerted by the ball causes the stationary marble to move. 1  Stop a moving object. The force exerted by the boy stops the moving baseball. Change the shape of an object, bend or break it. The forced exerted by the girl broke the twig and changed its shape. Change the direction of a moving object. The shuttlecock changes direction due to the force exerted by the two children when they hit the shuttlecock with their rackets. 2  Change the speed of a moving object. Ball B speeds up when Ball A pushes it in the same direction that it was rolling in. 4. When an object does not move, it shows that all forces acting on it are balanced. The wooden block remains stationary as the forces applied by the two people are equal. 5. Energy is needed for a force to be exerted. TYPES OF FORCES? 1. Magnetic Force: Magnetic force is the force exerted by a magnet. A magnet has a North-pole and a South-pole. Magnetic force of attraction is the pulling force exerted when two unlike poles face each other or when a magnetic material is being attracted to a magnet. 3   Iron, steel, cobalt and nickel are magnetic materials. Unlike poles of magnets exert a pulling force towards each other. Magnetic force of repulsion is the pushing force exerted when two like poles face each other. Like poles of magnets exert a pushing force towards each other. Magnetic force is strongest at the poles of a magnet. Magnetic force cannot pass through magnetic materials like iron, cobalt, nickel and steel, but can pass through non-magnetic materials. Magnetic force can act from a distance. 2. Frictional Force: Friction is produced when two objects rub against each other. Friction acts in the opposite direction of motion. Effects of friction; 4   Friction can cause a moving object to slow down and come to a stop eventually. The friction between the rolling ball and the floor will slow the ball down and cause the ball to come to a stop eventually.  Friction produces heat The friction between the palms produces heat.  Friction causes wear and tear The friction between the tyre and the ground causes the trend on the tyre to wear off. Friction wastes energy as energy is needed to overcome friction in machinery or even in our daily chores. 5  Friction is also useful as it allows us to;  Grip things without dropping them.  Drive a vehicle without the vehicle skidding  Walk without slipping  Stop moving objects The friction between the boy and the surface of the slide causes him to come to a stop. 6  The amount of friction between two surfaces depends on the roughness/ smoothness of the two surfaces. The rougher the two surfaces, the greater the friction between them. Friction can be reduced by using lubricants, rollers or wheels Air resistance is the force of the air pushing against a moving object. Water resistance is the force of the water pushing against a moving object as it moves through water. Friction cannot act from a distance. 3. Gravitational Force (Gravity): Gravity is the pulling force exerted on objects by the Earth. Weight is the measure of gravitational force on an object. Thus we are weightless in places where there is no gravity. Weight and mass are different. Mass is the amount of substance in an object. Mass does not change with the position of an object but weight changes with the position of an object. Gravity prevents objects from floating into space. Parachutist falling back to Earth 7  Bungee jumping Fruit falling onto the ground Gravity can act from a distance. 4. Elastic Spring Force: Elastic spring force is the force exerted by a compressed or an extended spring. A compressed spring exerts a pushing force while a stretched spring exerts a pulling force. The heavier the object compressing or stretching the spring, the greater the compression or extension, and the greater the force exerted. A spring cannot be compressed or extended further than its elastic limit. Elastic spring force cannot act from a distance. 8