Al Kamal American International School Force Pairs PDF

Al Kamal American International School – Halwan Worksheet Review – Assessment 1. Lessons: Force Pairs + Gravitational Force Name: ____________________________________...

Al Kamal American International School – Halwan Worksheet Review – Assessment 1. Lessons: Force Pairs + Gravitational Force Name: ____________________________________ Grade/Section: __/___ Date: / /2025 Curriculum standards: MS-ESS1-4 Success Criteria: 1- Students can define and explain Newton's Third Law and Gravitational Force with examples. 2- Students can Apply Formula for Weight: Students should correctly use 𝑊 = 𝑚𝑔 in problem-solving. 3- Students can identify scenarios demonstrating action-reaction forces. 4- Students can analyze the effects of changes in mass or distance on gravitational force. Lessons summary: Force Pairs Newton's Third Law: Definition: Newton's Third Law states that for every action, there is an equal and opposite reaction. Explanation: When one object applies a force on another, the second object applies an equal force in the opposite direction. Examples: Force Pairs: Definition: is the forces two objects apply to each other. Collision Forces: Forces that act during a collision, transferring energy and often resulting in momentum change. Types of Collisions: Elastic collision: When colliding objects bounce off each other. Inelastic collision: When objects collide and stick together. Science Department Worksheet Review / Science Grade: 8 Term 2 2024-2025 School Vision: A leading international school which empowers a new generation of academically distinguished individuals who are morally inspired and skilful in facing challenges through a comprehensive and high-quality education system.  Gravitational Force Gravitational Force: Definition: A noncontact force of attraction between two objects with mass. Weight and Mass: Mass: The amount of matter in an object (measured in kg). It is constant everywhere in the universe. Weight: The gravitational force acting on an object (measured in N). It depends on gravity and can vary based on location. - Formula: W= mg, where g is gravitational acceleration (9.8 𝑚⁄𝑚2 on Earth). Contact and Noncontact Forces: Contact Forces: Forces that require physical contact between objects. Examples include friction, tension, normal force, and air resistance. Noncontact Forces: Forces that act at a distance without direct contact. Examples include gravitational force, magnetic force, and electrostatic force. Normal Force: Definition: A contact force exerted by a surface to support the weight of an object resting on it. It acts perpendicular to the surface. Questions: Level 1: Basic Questions Fill in the Blank: Fill in the blank with the correct words. (Perpendicular - friction – 𝟗. 𝟖- m - increases - mass - south - mass - distance - north) 1- Weight depends on __ mass __ and gravitational acceleration. 2- The normal force acts __ Perpendicular _ to the surface. 3- Gravitational acceleration on the Earth is about ___9.8_ 𝒎⁄𝒔𝟐. 4- Contact forces include _ friction __ and tension. 5- Gravitational force decreases when the distance between two objects _ increases_. 6- The formula to calculate weight is W=_m_×g. 7- Gravitational force differs based on two things. It increases with increasing… mass...It decreases with increasing … distance … 8- Based on Newton's third law of motion, when a person on a skateboard throws a heavy concrete block to the north, the person will be pushed to the … south... True or False: 9- Gravitational force is a contact force. ( True / False ) 10- When you push a pole downward on Earth to make a pole vault, Earth exerts an equal force on the pole. ( True / False ) 11- Weight depends on gravitational acceleration. ( True / False ) 12- Normal force always acts perpendicular to a surface. ( True / False ) 13- Weight and mass are the same. ( True / False ) 14- In an inelastic collision, objects stick together. ( True / False ) 15- If you throw a ball into the air, Earth exerts a force on the ball. The ball in the air exerts no force on Earth. ( True / False ) 16- On the Moon, a person’s mass changes. ( True / False ) 17- A heavier object experiences a smaller gravitational force. ( True / False ) Level 2: Intermediate Questions Science Department Worksheet Review / Science Grade: 8 Term 2 2024-2025 School Vision: A leading international school which empowers a new generation of academically distinguished individuals who are morally inspired and skilful in facing challenges through a comprehensive and high-quality education system.  Multiple Choice Questions: Choose the correct answer from the choices for each question. 27- There is a gravitational force between you and your desk. This gravitational force is very small because _____ a) the masses are tiny compared to Earth's mass b) it doesn’t need to be large c) the distance between the objects is small d) it is a noncontact force 28- Mass and weight are different. Mass depends on _____. Weight depends on _____. a) gravitational force, the amount of matter b) placement, force c) force, placement d) the amount of matter, gravitational force 29- Gravity is an example of which kind of force? a) contact b) noncontact c) speed d) direction 30- If you push on a wall with a force of 20 N, the force acting on you from the wall is which of the following? a) 𝟎 N b) 𝟏𝟎 N c) 𝟐𝟎 N d) 30 N 31- A planet is discovered that has twice the mass of Earth but the same gravitational acceleration. If you weigh 700 N on Earth, on the new planet you would weigh ____. a) 350 N b) 700 N c) 1400 N d) 2800 N 32- Pick the best example of Newton’s third law of motion in action. a) A rocket accelerating in space as a result of gases and the rocket pushing each other in opposite directions. b) A rocket being towed to the launch pad while friction acts in the opposite direction. c) An asteroid moving around the Sun while being pulled toward the Sun. d) An asteroid continuing to spin because nothing has exerted a force to stop it. Problems on 𝑾 = 𝒎𝒈, 36- An object has a mass of 25 kg. What is its weight on the Moon (g=1.6 m/s2)? ………𝑊 = 𝑚𝑔 = 25 × 1.6 = 40 𝑁. …………………………………………………………………… 37- Calculate the weight of the object. Then, apply scientific understanding to draw a free-body diagram of the system. A book with a mass of 5 Kg is at rest on top of a desk. … 𝑊 = 𝑚𝑔 = 5 × 9.8 = 49 𝑁. …………………………………………………………………… 38- A person weighs 600 N on Earth. What is their mass? 𝑊 600 ………………… 𝑚 = 𝑔 = 9.8 = 61.22 𝐾𝑔.………………………………………… Level 3: Advanced Questions Open Ended Questions: Answer the following questions in complete sentences: Science Department Worksheet Review / Science Grade: 8 Term 2 2024-2025 School Vision: A leading international school which empowers a new generation of academically distinguished individuals who are morally inspired and skilful in facing challenges through a comprehensive and high-quality education system.  39- Compare Elastic and Inelastic Collisions. ……………… Elastic collision: When colliding objects bounce off each other. Inelastic collision: When objects collide and stick together.…………………………………………… 40- Compare Contact and noncontact forces. ……………… Contact Forces: Forces that require physical contact between objects. Examples include friction, tension, normal force, and air resistance. Noncontact Forces: Forces that act at a distance without direct contact. Examples include gravitational force, magnetic force, and electrostatic force.……………………………………………… 41- Your friend stated that action and reaction force pairs do not change motion because they cancel one another out. Explain why your friend is incorrect, using an everyday example to clarify your explanation. In your response, identify which of Newton’s laws of motion applies to action and reaction forces. Contrast action and reaction force pairs and balanced forces. … Action and reaction forces act on different objects, so they do not cancel each other out.… ……… Example: In rocket propulsion…………… 42- Define Gravitational Force. …………… A noncontact force of attraction between two objects with mass ……………………………………………… 43- Ahmed watched a video of someone using a jetpack rocket at a lake. Water is pumped out of the lake into the jetpack, and then the water is fired out of the jetpack, as shown in the picture. The rider is lifted out of the water and can move around over the lake. Explain how the height of the rider above the water could be increased. Support your explanation using Newton’s third law of motion. …………… According to Newton’s Third Law, increasing the force of the expelled water downward increases the upward force on the rider, lifting them higher. This can be achieved by increasing the water pressure or flow rate. ………………………………………… 44- reflection and feedback: Student’s Science Department Worksheet Review / Science Grade: 8 Term 2 2024-2025 School Vision: A leading international school which empowers a new generation of academically distinguished individuals who are morally inspired and skilful in facing challenges through a comprehensive and high-quality education system.