Force and Motion - Study Materials

Forces and Motion/ Simple Machines EOG Review Name: 1. Date: Susan gently pushes the tip of her nger against the eraser on her pencil and the pencil does not move. Which of the following gures best illustrates the interaction of forces between Susan's nger and her pencil? Driving Home Newton's Laws of Motion 2. Automobiles, baseballs, skateboards and bicycles — the world is full of things that are in motion. Centuries ago the British physicist Sir Isaac Newton stated three laws that describe the ways in which things move. These are Newton's three laws of motion: A. The rst law: Unless acted upon by an outside force, a body at rest tends to stay at rest, and a body in motion tends to stay in motion. B. The second law: Acceleration is equal to the net force acting on a body divided by its mass. The third law: For every action force there is an equal and opposite reaction force. C. A driver starts her car and steps on the gas pedal. The car gradually accelerates to 50 km/hr. A few minutes later, the driver suddenly slams on the brakes to avoid hitting a box in the road. As the car comes to a stop, the driver's body appears to lurch forward in the seat until it is restrained by the seatbelt. D. What law best explains why the driver's body appears to lurch forward when the brakes are suddenly applied? A. Newton's rst law B. Newton's second law C. Newton's third law D. The law of gravity page 1 5. Crash Test Smarties 3. Two forces act on the 2 kg box shown below. Modern automobiles are tested for collision safety using models of human beings often called crash test dummies. These “dummies” are actually quite “smart.” They are often tted with sensor devices that can record their motion and force of impact during an automobile collision. A 4 N force acts to the right and a 6 N force acts to the left. What is the net force acting on the box? In the diagrams shown below, the length of the arrow indicates the relative amount of force. Which of these diagrams correctly shows the amount and direction of the forces on the wall and the car during the collision? 6. A. B. 7. C. A. 10 N to the right B. 10 N to the left C. 2 N to the right D. 2 N to the left A 1500 kg car increases its speed by 2 m/s for each second of travel. What is the net force acting on the car? A. 750 N B. 1500 N C. 3000 N D. 6000 N The forces acting on a skateboarder moving at a constant velocity along a sidewalk are shown in the gure below. D. 4. Which of the following is the net force on the skateboarder? Explain why a golf ball that is hit on the moon travels much farther than a golf ball that is hit with the same force on the Earth. page 2 A. 0N B. 70 N C. 670 N D. 1270 N Forces and Motion/ Simple Machines EOG Review 8. 9. The tendency of a stationary object to resist being put into motion is known as A. acceleration. B. C. weight. D. velocity. 11. inertia. The moon has a smaller mass than the Earth. If you were able to travel to the moon your weight would A. increase. B. descrease. C. remain the same. A family is moving from Pennsylvania to Connecticut during the summer. One of the movers tosses a small box to another mover across the room. The path of the box as it travels through the air will be curved downward due to . D. vary from day to night. 10. If you were able to go to the top of a tall building and simultaneously drop an apple and a basketball, they would both hit the gound at about the same instant because A. the force of gravity on them is equal. B. they have the same mass. C. air resistance on both is the same. A. its positive acceleration B. the force of gravity C. the inertia of the box D. its change in weight 12. D. they have the same amount of kinetic energy. How would the measurable properties of a golf ball change if it were moved from Earth to the Moon? A. It would have the same mass, but a di erent weight. B. It would have the same weight, but a di erent mass. C. It would have the same density, but a di erent mass. D. It would have the same mass, but a di erent density. page 3 Forces and Motion/ Simple Machines EOG Review 13. The diagram below shows some positions in the path of a pendulum swinging from a xed point called a fulcrum. 17. Use the following diagram of a pendulum to answer the following question(s). Which statement best describes the energy changes from A to B and then from B to C? The pendulum is raised to the start position and released. At which two numbered positions is the potential energy of the pendulum most likely the same? A. position 1 and position 3 B. position 1 and position 4 C. position 2 and position 3 15. 18. The force of gravity on an object depends primarily on the object's A. density. B. C. momentum. D. volume. B. Potential energy decreases from A to B and increases from B to C C. Kinetic energy decreases from A to B and increases from B to C Which of the following objects acts as a lever when pulling a nail? mass. What is the mass of an object weighing 63 N on Earth? A. 16. Total energy decreases from A to B and increases from B to C D. Potential energy decreases from A to B and increases from B to C D. position 2 and position 4 14. A. 0.1 kg B. 6.3 kg C. 73 kg D. 617 kg The distance of the star Vega from Earth is 1.6 million times greater than the distance of the Sun from Earth. Which of the following best describes the gravitational in uence of Vega on Earth? A. It is roughly equal to that of the Sun. B. Its in uence is greater than that of the Sun. C. Its in uence is small because of its distance. 19. D. It in uences the magnitude of Earth's mass. page 4 A. hammer B. head of nail C. board D. point of nail Jonas needs to split a log. He has a sledge hammer. What other tool should he also use to split the log? A. a lever B. a pulley C. a wedge D. a fulcrum Forces and Motion/ Simple Machines EOG Review 20. The picture shows a ladder leaning against a wall. 22. The picture below shows a seesaw. A seesaw on a playground is an example of what type of simple machine? 23. A. lever B. screw C. wedge D. wheel and axle The picture below shows a pair of scissors. A person climbing this ladder is using the ladder as 21. A. a lever. B. a wedge. C. a simple gear. D. an inclined plane. Scissors are an example of a complex machine. Which of the following simple machines are combined to make scissors? The picture below shows a light bulb. A. lever and gear B. gear and pulley C. lever and wedge D. wedge and pulley The bottom of this light bulb is an example of what type of simple machine? A. a lever B. a pulley C. a screw D. a wedge page 5 Forces and Motion/ Simple Machines EOG Review 24. Which of the following objects does not have a wedge? 25. A. The diagrams below show a cart moving with a velocity, V, on a frictionless surface as a wooden block is being dropped. The block then falls straight down onto the moving cart. B. Which of the following statements describes what will happen after the block lands on the moving cart? C. A. The cart will move to the left at a velocity less than the original velocity of the cart. B. The cart will move to the left at a velocity greater than the original velocity of the cart. C. The cart will move to the right at a velocity less than the original velocity of the cart. D. D. The cart will move to the right at a velocity greater than the original velocity of the cart. page 6 Forces and Motion/ Simple Machines EOG Review 26. A cart with a mass of 5 kg rests on a oor next to a wall, as shown in the diagram below. 27. A person pushes on the cart to the left toward the wall with a force of 100 N. Which of the following statements is true in this situation? A. The wall does not push on the cart. B. The oor pushes 100 N up on the cart. C. The cart pushes 100 N down on the oor. A performer pulls a tablecloth out from under a complete set of dinnerware as shown in the illustration below. Which of the following best explains the performer's success at leaving all the dinnerware on the table? D. The wall pushes 100 N to the right on the cart. A. the inertia of the dinnerware B. the large mass of the tablecloth C. the placement of the dinnerware D. the rough material of the tablecloth 28. Four students push on a block of wood with the forces shown in the diagram below. Assume friction is negligible. The block slides horizontally. What is the net force acting on the block of wood? page 7 A. 3 N to the left B. 8 N to the left C. 11 N to the right D. 25 N to the right Forces and Motion/ Simple Machines EOG Review 29. Two people are each pulling on the opposite ends of a rope. If they are pulling on the rope with equal but opposite forces, what will happen to the rope? A. It will stay in place between the two people. B. It will move toward the right. C. It will move toward the left. 33. 34. D. It will fall to the ground. 30. 31. A student is riding a bike and applies the brakes. Which most helps the bike to stop? 35. A. friction B. gravity C. heat D. momentum An object is moving at a constant speed. If a balanced force is applied in the opposite direction the object is moving, what will most likely happen? A. 125.0 N B. 250.0 N C. 2,000. N D. 4,000. N A 100-N force causes an object to accelerate at 2 m/s/s. What is the mass of the object? A. 0.02 kg B. 50 kg C. 102 kg D. 200 kg A student in a boat decided to go for a swim. He dove o the back of the boat, as shown in the diagram. The boat moved in the direction shown by the arrow. Which statement best explains why the boat moved in the direction shown? A. The object will speed up. B. The object will change direction. A. A body in motion tends to remain in motion. C. The object will continue moving at a constant speed. B. The acceleration of a body is directly proportional to the force applied. C. For every action there is an equal and opposite reaction. D. The object will slow down and eventually stop moving. 32. How much force is needed to accelerate a 500.0-kg car at a rate of 4.000 m/s/s? D. Friction on the bottom of the boat was reduced because of the lake water. This diagram shows an object being pushed along a frictionless surface. The object accelerates at 2 m/s/s. 36. What force was applied to the object? A. 1N B. 1.5 N C. 5N What forces are equal in size but opposite in direction? A. balanced B. frictional C. gravitational D. unbalanced D. 6 N page 8 Forces and Motion/ Simple Machines EOG Review 37. A ball is dropped from the top of a tall building. As the ball falls, the upward force of air resistance becomes equal to the downward pull of gravity. When these two forces become equal in magnitude, the ball will A. atten due to the forces. B. fall at a constant speed. C. continue to speed up. 39. Use the information below to answer the question(s) below. A group of students investigated physics concepts at an ice-skating rink. The students skated at di erent speeds and pushed boxes across the ice. The boxes were exactly the same except for their mass. D. slow to a stop. 38. The graph below shows the velocity of a car that is moving in a straight line. MASS OF BOXES Box Mass (kilograms) During which of the following intervals are forces on the car balanced? A. q to r B. r to s C. s to t 1 45 3 70 2 D. t to u 4 60 85 What type of force causes an ice skater to begin to move? page 9 A. balanced B. gravitational C. magnetic D. unbalanced Forces and Motion/ Simple Machines EOG Review 40. If each wagon is given the same push, which wagon should go the fastest? 41. A. B. After more than 30 years, the spacecraft Pioneer 10 continues to travel through space, beyond the solar system. Which statement explains why this spacecraft continues to move? A. Pioneer 10 is in motion and will stay in motion. B. Pioneer 10 carries excess fuel to allow more motion. C. NASA astronauts are steering Pioneer 10. D. NASA has refueling missions to Pioneer 10. C. D. page 10 Forces and Motion/ Simple Machines EOG Review