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NEWTON’S LAWS STUDY GUIDE Name______________________________ LAW 1- If an object has balanced forces acting upon it, it will move at constant velocity. If the object has unbalanced forces acting upon it, it will accelerate. ! 1.Draw a qualitative force diagram for the following scenario (label all forces): A car is accelerating rightwards. There is friction from the ground. ! ! ! ! ! 2. Draw a qualitative force diagram for the following scenario (label all forces): A car is coasting to a stop while moving rightwards (NO MORE GAS). There is friction from the ground. ! ! ! ! ! ! ! 3. Draw a qualitative force diagram for the following scenario (label all forces): A car is moving at a constant velocity on the highway. There is friction from the ground and from the air. ! ! ! ! ! ! ! ! ! 4. Find the net (overall) force on each object. 5. Imagine that an astronaut in space throws a rock (and he is far away from any gravitational pulls, no friction, ect). Due to Newton’s 1st Law, what will the motion of the rock be after it is released from the astronaut’s hand? Explain. ! ! ! ! ! 6. Imagine that you have a bowling ball and an equally-sized tennis ball in the seats of a car going 100 Km/h. If the car slams on its brakes, which object is going to go farther? Explain. ! ! ! ! ! ! 7. Imagine that you are swinging a ball around your head on a string in a circular motion. You release the ball and the string at the top of its loop (as shown). Which path will the ball take once you release it, 1, 2, or 3? EXPLAIN. ! ! ! ! ! ! 8. Consider the following motion map. ! Is the object in this motion map experiencing balanced or unbalanced forces? Explain how you know. ! ! ! ! 9. Which object(s) in the Position vs. time graphs below is(are) experiencing unbalanced forces? Which object(s) is(are) experiencing balanced forces? Explain how you know. ! ! ! ! ! LAW 2- A greater force is required to accelerate a greater mass. OR a greater force creates a greater acceleration OR F=MA ! 1. Find the overall acceleration for a scooter that has a mass of 20 kg, with a pushing force of 100 N right and frictional forces of 20 N. ! ! ! ! ! ! ! 2. Imagine that a bobsled team wants to accelerate their bobsled 15 m/s^2. It has a mass of 250 kg. What force must they apply to the bobsled (in the absence of friction)? ! ! ! ! ! 3. A 100 kg biker accelerates right at 2.0 m/s2. He is experiencing 10 N friction from the ground. Determine the overall force and use this information to determine the quantitative force diagram. ! ! ! ! ! ! ! ! ! 4. Imagine that you are sitting next to two strollers with babies in them. Baby one (with stroller) is 5 Kg and Baby two (with stroller) is 7 Kg. If you push both babies with an equal force, and baby one accelerates at 4 m/s2, then how fast will baby two accelerate? (HINT: This is a 2-step problem) ! ! ! ! ! ! ! ! ! ! 5. Imagine that you have a bowling ball and a soccer ball that are on an ice rink. If you push both objects with a force of 50 N, compare the motion that each object will have. Explain how you know. ! ! ! ! ! ! 6. You are pushing on a 50 kg moving box with 50 N of force, and it is sliding to the right at a constant velocity. Create a quantitative force diagram for this situation below. ! ! ! ! ! ! 7. An elevator is moving up at a constant velocity of 2.5 m/s, as illustrated in the diagram below: The passenger has a mass of 85 kg. Make a force diagram for the passenger.What force does the floor exert on the passenger? ! ! ! ! 8. A powerlifter in the olympics knows that he can generate 2000N of force with his muscles. What would be the greatest mass that he could lift? ! ! ! ! ! ! 9. Jack is holding a 0.1 kg Justin Bieber CD by accident, when a friend of his walks up. In an attempt to look cooler, Jack throws the CD with a force of 10 N. What was the acceleration of the CD when Jack threw it in a fit of coolness? (4 pts) (Please make your own list) ! ! ! ! 10. Jarod is sledding down a hill trying to hit a group of wild rabbits. He starts down the hill with an initial velocity of 0 m/s. In 20 seconds, he has a velocity of 10 m/s. What is Jarod’s acceleration towards the rabbits? (4 pts). ! ! ! 11. If an airplane is traveling at a rate of 83 km/h to the east, and you walk to the front of the airplane at a rate of 7 km/h, what is your overall velocity (speed and direction)? (2 pts, show work) ! ! ! ! 12. ______Imagine that a car is driving forward, and it has a tennis ball, a bowling ball, and a ping pong ball on the front. If the car accelerates at 25 m/s2 and then slams on the breaks, which of the objects will fly the farthest? Consider the force of drag. (HINT: Think inertia) ! a) Ping Pong ball distance b) tennis ball c) bowling ball d) they travel the same ! ! 13. ______Imagine that the car is now driving forward On THE MOON, and it has a tennis ball, a bowling ball, and a ping pong ball on the front. If the car accelerates at 25 m/s2 and then slams on the breaks, which of the objects will fly the farthest? DO NOT consider the force of drag. (HINT: Think inertia) ! a) Ping Pong ball distance b) tennis ball c) bowling ball d) they travel the same ! ! 14._____ Imagine that Alexis has a mass of 55 kg on earth. If she travels to the moon, what will her mass be there? ! a) Greater than 55 kg information b) Less than 55 kg c) 55 kg d) not enough ! 15. _____ John throws a ball straight forward and drops another ball at the exact same time. Select the statement that will be true in this situation. ! ! a) The ball that is dropped will hit the ground first. b) The ball that is thrown forward will hit the ground first. c) Both of the balls will hit the ground at the exact same time. d) There is no possible way that John can measure which one will hit first. 16._____Mrs. Mumaw goes skydiving in a place with air resistance. If she has already reached terminal velocity, what is her acceleration at that point? a) 9.8 m/s2 acceleration ! ! b) less than 9.8 m/s2 c) more than 9.8 m/s2 d) no 17. A shopping cart with mass of 10 kg is being pushed with a rightward force of 100 N. There is friction between the cart and the ground of 10 N. There is no air resistance. Please diagram ALL of the forces acting on the cart. (HINT: Kg is not the unit for force! Solve for the weight). ! ! ! ! ! What is the overall force and direction of the cart?___________________ 18. A ball with a mass of 2 kg is falling in the air straight downwards. Air resistance is 5 N. Draw a force diagram, and solve for the overall (net) force magnitude and direction. ! ! ! ! ! ! Net Force: ______________________ 19. Two men push on a box with a force of 48 N. One man is pushing from the left, the other man is pushing from the right. If the box has a mass of 45 kg, create an appropriate force diagram. ! ! ! ! ! Net Force: ____________________
