GRADE 8 PHYSICS , VERY EASY

GS UnIt 1 L\" @13ng .'_'.le9.le QLIJI-'LD Force and Motion . / Emirates National Schools Summatlve- Criteria A Level 1-2 Questions 1. During a baseball game, a hitter strikes the ball with a bat. When this happens, the ball and the bat exert a force on each other. Why does the ball accelerate away from the bat more than the bat accelerates away from the ball? Choose the correct answer. A. The ball has less mass, so it exerts less force on the bat. B. The ball has greater velocity before the collision, so the force affects the ball more than it affects the bat. C. The ball has less mass, so the equal force on the ball and the bat causes greater acceleration of the ball. D. The bat exerts more force than the ball because the batter is exerting a force on the bat as it hits the ball. 2. One marble is moving and collides with a stationary marble. Which of these statements is true? Choose the correct answer. A. Each marble exerts a force on the other, and the two forces are equal and in opposite directions. B. Each marble exerts a force on the other, and the two forces are the same in magnitude and direction. C. Each marble exerts a force on the other, and the two forces are proportional to the masses of the marbles. D. The moving marble exerts a force on the stationary marble, but the stationary marble does not exert a force on the moving marble. 3. A soccer player kicks a ball. The player's foot exerts a force on the ball. The ball exerts a force on the foot. Why don't the forces cancel out to result in a net force of zero? Choose the correct answer. A. The ball moves before the forces can cancel out. B. The forces become unbalanced due to air resistance. C. The force on the ball is greater tha n the force on the foot. D. The forces are exerted on different objects, and neitherforce is zero. 4. Why is friction force considered a contact force? Choose the correct answer. A. Friction affects only solid objects. B. Friction always acts in the same direction. C. Friction is produced when objects slide past one another. D. Friction acts in a direction opposite to the direction of an object's motion. (:8 \"mt 1d M t. y Lsdo" ..' 9J| QIJLo-l-ll gulls... orce an. 0 ion . / Emirates National Schools Summatlve- Criteria A 5. Sandra pushed a wooden block and it slid across the oor. The wooden block gradually slowed down and stopped after moving 10 meters. Why did the block stop moving? A. The floor exerted a force that is opposite to the direction of the block's motion. B. The block ran out of force. C. The floor absorbs force from the block. D. All objects stop moving because their natural state is to be still. 6. At dinner, Hans passed the saltshaker to his sister Jessica by sliding it across the wooden table. The saltshaker gradually slowed down and stopped after moving 12 centimetres. Why did the saltshaker stop moving? A. The saltshaker ran out of force. B. The table exerts a force that is opposite to the saltshaker's motion. C. The table absorbs force from the saltshaker. D. All objects stop moving because their natural state is to be still. Level 3-4 Questions 7. What are the ve ways an object's motion can change? One response has been lled in to help you get started. I sta rt moving 8. Why does an object that is sliding across carpet slow down? 68 Unit 1 _ .. 0 Ludo | " | LoJJl l Force and Motion & -- 9-1 |-'J . on] M Summative Criteria A 9. Emirates National Schools Imagine you push a book across an incredibly slippery surface. It slides right across because there is no friction. Next, you push the same book across a rougher surface that exerts friction. Will the velocity ofthe book change as it moves across the surface with no friction? Explain you r a nswe r. 10. Scott and James work at a grocery store. After the grocery store closed, they were playing a game with a shopping cart and Scott's skateboard. They crashed the skateboard and the shopping cart two times. The shopping cart had more mass in Crash 2 than it did in Crash 1. Use the information in the diagram to answer. Before Afte r Cras h 1 up w W W 0 to Cart. .css Mass CaiL MovingE m/s Moving 5 mfs (sped up by 3 ms) C rash 2 its. .. W Cart. More Mass Cart Moving ms Mowng Emfs [sped up by 3 ml:} In which crash did the skateboard experience a strongerforce? A. The skateboard did not experience a force; onlythe shopping cart experienced a force in the crashes. Crash 2; the force on the cart was stronger inthis crash, so the force on the skateboard was also stronger. The diagram doesn't tell you anything about the force on the skateboard. It only gives information about the force on the shopping cart. The skateboard experienced the same force in both crashes. The shopping cart changed speed by the same amount in each crash, so the force on the skateboard was the same each time. GS UnIt 1 .- . ai+1Jg9J| QIJprl dull\" Force and Motion . Emirates National Schools Summatwe Criteria A 11. Miniature golf is a game in which players hit a golf ball with a club, which causes the ball to roll along the at ground. Three golf balls with the same mass were rolling on the ground. Each ball was hit by a golf club, but not from the same direction. All the golf balls changed speed as a result of being hit. Use the information in the diagram to answer. Before After Purple Ball Speed: 8 m/s Purple Ball Speed: 12 m/s {sped up by 4 m/s) Whlte Ball Speed 14 m/s {sped upbyd m/s) Green Ball Speed: 16 ms Green Ball Speed: 10 m/s (slowed clown by 6 m/s) Which golf ballls} experienced the strongest force when hit? How do you know? A. The white and purple golf balls because they gained force, while the green golf ball lost force. B. The green golf ball because it takes a strongerforce to slow something down than to speed something up. The green golf ball because it changed speed the most. D. The white golf ball because it has the fastest ending speed. E"? G8 Unit 1 Force and Motion aliboll ulj Loul Jujkso Summative- Criteria A Emirates National Schools Level 5-6 Questions 12. Three toy boats with the same mass were in a lake. Two boats were moving, and one was stopped. Each boat got bumped by another boat, but not in the same direction. All the boats changed speed as a result of being bumped. Use the information in the diagram to answer. How do you know? Before After Blue Boat Speed: 8 km/h Blue Boat Speed: 3 km/h (slowed by 5 km/h) Orange Boat Speed: 0 km/h Orange Boat Speed: 5 km/h (sped up by 5 km/h) Gray Boat Speed: 12km/h Gray Boat Speed: 17 km/h (sped up by 5 km/h) a. Which toy boat(s) experienced the strongest force when it was bumped? b. How do you know?G8 Unit 1 . .. . CLLJJ: I " I LoJJI I Force and Motion a 9-] \"J. ' on] M Emirates Natlonal Schools Summative Criteria A 13. Mateo and Jackie were on a playground rolling some different-sized balls to get them to crash. They used a tennis ball (the same mass) in both crashes. They tried two soccer ballsa pink one (more mass) for Crash 1 and a blue one (less mass) for Crash 2. Mateo and Jackie want to know what happened to the tennis ball. Use information from the 14. diagram to answer. Before Crash 1 Pink Ball: More Mass Moving 12 m/s Crash 2 Blue Ball: Loss Mass Moving 12 m/s In which crash did the tennis ball experience a strongerforce? After \\QJL :2/ Pink Ball: Moving 15 mm (sped up ray .3 m/s) 'o ._1 Blue Ball. Moving 15 mic. (sped up Dv3 m/c) How do you know? Hockey is a sport in which players use hockey sticks to push a puck across smooth ice. At practice one day, three different-coloured hockey pucks were sliding on the ice. The green hockey puck has less mass than the black and purple hockey pucks, which have the same mass. A player hit each hockey puck with a stick, but not from the same direction. Use the information in the diagram to answer. GS Unit 1 Force and Motion Summative Criteria A 15.-lbw auprI MI\" Emirates National Schools Before After Green Puck: 100 g (Less Mass) Speed: 24 m/S Speed: 14 m/s (sped up by 10 m/s) Black Puck:1?0 g (More Mass) Speed: 30 m/s Speed: 20 m/s _ (sped up by 10m Is) Purple Puck;1?0 3 {More Mass) Speed: ? m/s Speed: 17 m/s (slowed down by 10 m/s) 51. Which puckls} experienced the strongest force when hit? b. How do you know? Level 7-8 Questions 15. A satellite was in two separate crashes. In both crashes, the satellite had the same mass. Engineers want to know about the speed and direction of the satellite after the crashes. Satellite Crash] Crash 2 X Black Aetermd. more mass Gray Asteroid. less mass SloweddownnyEkm/s Slowed down hy2 km/s G8 Unit 1 Force and Motion aliboll ulj Loll JuJIso Emirates National Schools Summative- Criteria A a. Why would the crash affect the motion of the satellite? b. which crash caused a greater change in motion for the satellite? 16. In a warehouse, the workers sometimes slide boxes along the floor to move them. Two boxes were sliding toward each other and crashed. The crash caused both boxes to change speed. Based on the information in the diagram, which statement is correct? In your answer, explain what the forces were like and why the boxes changed speed. . Box 1 has more mass than Box 2. . Box 1 and Box 2 are the same mass. . Box 1 has less mass than Box 2. Before Crash After Crash Box 1: Box 2 Box 1: Moving 2 km/hr left Box 2: Moving 1 km/hr left Moving 4 km/hr right Moving 8 km/hr left (changed speed by 6 km/hr) (changed speed by 7 km/hr) a. which statement is correct? b. explain what the forces were like and why the boxes changed speed.G8 Unit 1 Force and Motion aliboll ulj Loul Jujlso Emirates National Schools Summative- Criteria A Criterion A: Knowing and understanding 1. Describe scientific knowledge ii . Apply scientific knowledge and understanding to solve problems set in familiar and unfamiliar situations iii. Analyse information to make scientifically supported judgments. Achievement level Level descriptor Questions The student does not reach a standard described by any of the 0 descriptors below The student is able to: 1-2 i. recall scientific knowledge 1,2,3,4 ii. apply scientific knowledge and understanding to suggest 1-2 solutions to problems set in familiar situations 5,6 iii. 1-2 apply information to make judgments The student is able to: 3-4 i. state scientific knowledge 7,8. ii. apply scientific knowledge and understanding to solve 3-4 problems set in familiar situations 10,11 iii. 3-4 apply information to scientifically supported judgements 9 The student is able to: 5-6 i. outline scientific knowledge ii. apply scientific knowledge and understanding to solve 5-6 problems set in familiar situations and suggest solutions to 12a, 13a, 14a problems set in unfamiliar situations iii interpret information to make scientifically supported 5-6 judgments. 12b, 13b, 14b The student is able to: 7-8 i. describe scientific knowledge 15a, 16a ii. 7-8 apply scientific knowledge and understanding to solve problems set in familiar situations and unfamiliar situations 7-8 iii. analyse information to make scientifically supported 15b, 16b judgments