6th Grade U4 Exam PDF

# 6th Grade U4 Exam ## 1. According to Newton's third law of motion, if someone jumps off a skateboard, the skateboard will roll backward because - *** - A) The mass of the skateboard is the same as the mass of the person jumping off. - B) The pull of gravity on the person is the same as on the...

# 6th Grade U4 Exam ## 1. According to Newton's third law of motion, if someone jumps off a skateboard, the skateboard will roll backward because - *** - A) The mass of the skateboard is the same as the mass of the person jumping off. - B) The pull of gravity on the person is the same as on the skateboard, regardless of size. - C) The air resistance on the person is great and the friction on the skateboard is small. - **D) The force that sent the person forward, there is an equal force pushing back on the skateboard.** *** ## 2. Which two characteristics are most useful for determining its elastic potential energy of a stretched rubber band? *** - A) The length to which the rubber band is stretched and the mass of the rubber band - **B) The length to which the rubber band is stretched and the force used to stretch it** - C) The mass of the rubber band and the force used to stretch it - D) The force used to stretch the rubber band and its height above the ground *** ## 3. A 200-gram mass is attached to a spring. The spring is attached to a stand that rests on a table. Image shows a 200 gram mass attached to a spring, which is attached to a stand that rests on a table. The elastic potential energy of the spring would be changed if which of the following changes were made? *** - **A) Replacing the mass with a 400-gram mass** - B) Attaching the spring closer to the stand - C) Using a stand that is 50 centimeters tall - D) Moving the stand to a taller table *** ## 4. Some forms of potential energy are stored in the bonds between atoms and molecules, stored inside the nucleus of an atom, stored in a compressed or stretched object, or stored in the gravitational field between an object and Earth. A diagram of a moving pendulum is shown below, with 5 positions labelled 1 to 5. Which position of the pendulum would have the least amount of potential energy? *** - A) 1 and 5 - B) Only 3 - **C) 2 and 4** - D) Only 5 *** ## 5. Two objects are sitting on a table. Which of the two objects will have the greater gravitational potential energy? *** - A) The larger object - B) The smaller object - **C) The object with more mass** - D) The object with less mass *** ## 6. Which graph correctly shows the relationship between an object's height from the ground and its gravitational potential energy (PE)? Four graphs show relationship between height and potential energy: - **A) A linear graph with positive slope** - B) A horizontal linear graph - C) A triangular graph with peak at the highest height - D) A triangular graph with peak at the lowest height ## 7. An amusement park ride uses electricity to make its motor spin. The ride also makes noise and lights up. Which observation of the amusement park ride demonstrates the law of conservation of energy? *** - A) The amount of energy used by the amusement park ride is greater than a water-log ride. - **B) The amount of electrical energy used equals the total amount of mechanical, sound, and light energy produced.** - C) The amusement park ride only uses energy when it has a full group of riders on it. - D) The amount of energy used by the ride is less than the total amount of energy produced as the motor spins. *** ## 8. Energy is always conserved. It cannot be created or destroyed. It can, however, be transferred between objects or systems, from one form to another. Which of the following is true of the relationship between kinetic and potential energy? *** - A) When a system loses kinetic energy, it loses potential energy. - B) As kinetic energy decreases, potential energy decreases. - **C) When a system gains kinetic energy, it loses potential energy.** - D) As kinetic energy increases, potential energy increases. *** ## 9. Students conducted an investigation in which they rolled marbles across different surfaces to measure the effect of the force of friction on each surface. Friction slows down and stops objects. Which of the surfaces investigated showed the greatest amount of friction? (Click on the letter of the correct surface.) A bar chart shows the distance a marble rolled on different surfaces labelled A to D. *** - **D) The surface that the marble travelled the shortest distance.** *** ## 10. Two students, John and Taylor, pull in opposite directions, but neither move positions. An image is provided. Which of the following best describes the forces being applied in this situation? *** - A) The forces are balanced, and the net force is positive. - B) The forces are unbalanced, and John applies a greater force. - C) The forces are unbalanced, and Taylor applies a greater force. - **D) The forces are balanced, and the net force is zero.** *** ## 11. Two magnets pull on each other. What would make the magnets pull with less force? *** - A) Use two stronger magnets - B) Add heat to one magnet - C) Turn both magnets around - **D) Move the magnets further apart** *** ## 12. James is investigating magnets and movement. He has two magnets and an iron nail. If James wants to illustrate how magnetic force can make things repel each other, which arrangement of objects should he use? Four diagrams are shown of magnets and a nail arranged differently. *** - **A) Two magnets facing the same pole (North or South) with nail in the middle.** *** ## 13. A box and magnitudes of forces are shown below. A box rests motionless on the ground. One student is pushing the box to the right with a force of 25 Newtons. The other student is pushing to the left with a force of 10 Newtons. In which direction and with what force will the box move? Image shows one student pushing the box to the right with 25 Newtons force and another to the left with 10 Newtons force. *** - It will move to the **right** with a net force of **15** Newtons. *** ## 14. A boy pulls a wagon with a force of 6 Newtons east as another boy pushes it with a force of 4 Newtons east. What is the net force? *** - The net force = **10** Newtons. *** ## 15. What is the net force acting on the box? Image shows a box being pulled to the right with 50 N and friction acting on it to the left with 10 N. *** - The net force is **40** Newtons to the **right**. *** ## 16. A diagram of forces being applied to a box by four people is illustrated below. If the net force acting on the box is 10 N to the right, what is the magnitude of the force applied by the boy pulling to the left? Image shows four people pulling a box. Two people are pulling left with forces of 11 N and 8N. Another two are pulling right with forces of 21 N and unknown force. *** - The magnitude of the boy pulling to the left is **20** Newtons. *** ## 17. A book rests on a table. The force of gravity pulls down on the book with a force of 20 newtons. What prevents the books from accelerating downward at 9.8 m/sec2? *** - A) The table presses back up on the book with an equal and opposite force of 20 newtons. - B) The table presses back up on the book with a force greater than 20 newtons. - C) The table and the book together are accelerating downwards at 9.8 m/sec2. - D) The inertia of the book holds it up. *** ## 18. Mr. Melendez’s science class were preparing to launch model rockets. Assuming the two forces on the model rockets are lift and gravity, which of the following diagrams would result in the rocket lifting? Four diagrams are shown. Each shows a rocket with lift force pointing upward and gravity downward. Each diagram has different magnitude for both forces. *** - Lift 35 Newtons and gravity 25 Newtons. *** ## 19. The diagram below shows a sled moving along a smooth, frictionless track. Image shows a sled travelling on a track with four sections labelled. In which sections of the track will the sled experience an unbalanced force? (Select two correct answers) *** - Section 1 - Section 3 *** ## 20. What is the net force acting on the box pictured? Image shows a box on a table with forces acting on it, horizontal forces of 10N and 5N to the right and 8N and 2N to the left. *** - 11 Newtons - to the right *** ## 21. Read the sentence carefully. Drag the correct term to the blank to complete the sentence. Newton’s third law states that an action will have a(n) **opposite** and **equal** reaction. ## 22. What is the net force of the box shown below? Image shows a box pushed to the right with 60N force and pulled to the left with forces of 40N and 30N. Select TWO correct answers. *** - 10 Newtons - to the right *** ## 23. An object is pushed across a flat surface as shown in figure one. Each arrow represents a force. Match the force to the correct arrow. Image shows a force acting on a box to the right with arrow labelled “?” and arrow labelled “?” for a normal force and friction force. *** - Applied force - Normal force - Frictional force *** ## 24. Students in a science class were asked to design an experiment to test how the type of material an object was made of affected the attraction of the object to a magnet. The students were given a ring magnet, a ruler, and objects such as a metal paperclip, a plastic bouncy ball, a wood bead, a metal nail, and a safety pin. Complete the IVCDV chart below. | Independent Variable | Constants | Dependent Variable | |---|---|---| | Type of material objects are made of | Distance the object and magnet are from each other, Attraction or no attraction of the magnet and the object, Size of magnet | Type of magnet | ## 25. Compare and contrast gravitational potential energy to elastic potential energy. **Gravitational potential energy** is the energy an object possesses because of its position relative to a gravitational field. **Elastic potential energy** is the energy stored in a deformed elastic object, such as a stretched rubber band or a compressed spring. Both are forms of potential energy, meaning they are stored energy that can be converted into kinetic energy. However, they are stored in different ways and depend on different factors. Gravitational potential energy depends on the mass of the object, the acceleration due to gravity, and the object's height above a reference point. Whereas, elastic potential energy depends on the material's elastic properties, the amount of deformation, and the object's stiffness.