Worksheet : Newton's 2 nd Law Name 1. A water skier has a mass of 79 kg and accelerates at 1.4 m/s2. What is the net force acting on him? F- ma = 79 4x x 104 m/52 2 HIN FIma = 76 x 1. ym's = 1IN 2. What is the mass of an object if it takes a net force of 32 N to accelerate it at a rate of 0.88 m/s?? 3. A net force of 15 N is applied to a cart with a mass of 2.1 kg. a. What is the acceleration of the cart? b. How long will it take the cart to travel 2.8 m, starting from rest? 4. What is the acceleration of a box weighing 666 N if a force of 777 N is applied to it? PHYSICSFundamentals 2004, GPBName Worksheet: Newton's 2nd Law 5. A car has a mass of 820 kg. It starts from rest and travels 41 m in 3.0 s. What is the net force applied to the car? 6. What is the net force needed to lift a full grocery sack (weighing 210 N) uniformly? What is the net force needed to accelerate the grocery sack upward at 1.5 m/ s'? 7. If 2.2 Ibs = 1.0 kg, and Megan Progress weighs 130 lbs, what is her weight in newtons? 8. What will be the final velocity of a 5.0 g bullet starting from rest, if a net force of 45 N is applied over a distance of 0.80 m? PHYSICSFundamentals 2004, GPB 4-05Worksheet: Newton's 3d Law Name 1. Newton's 3"d Law is known as the Law of Whenever one body exerts a on the second body, the second body exerts an force in the direction. 2. In every interaction, forces occur in. For example, when you walk across the floor, you push the floor (forward, backward) and the pushes you (forward, backward). The action/reaction forces do not cancel out because. objects are involved, each experiencing a force. 3. When a kicker kicks a football with a force of 100 N, the ball The effects are different because the kicker has more and therefore accelerates (more, less). 4. If you are weighing yourself while standing next to the bathroom sink, and you pull upward on the sink, your weight will appear to be (more, less) because the sink on you. 5. For the following action forces, give the reaction forces: a. Hammer hits nail. b. Earth pulls down on falling leaf. C . Falling leaf pushes air down. d. Man pushes elephant forward with a force of 500 N. 6. Look at the diagram on the right. The earth pulls down on the girl and the ropes pull up on her with equal force. The net external force on the girl is Why is this not an example of an action/reaction pair? State the two action/reaction pairs of force involving the girl: PHYSICSFundamentals 2004, GPB 4-11