Newton s Laws Student Success Sheets (SSS)

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--- Newton s Laws unit student success sheets--- Page 1 Newton s Laws Student Success Sheets (SSS) HS-PS2-1 HS-PS2-2 NGSS Civic Memorial High School - Physics Concept # What we will be learning

1 --- Newton s Laws unit student success sheets--- Page 1 Newton s Laws Student Success Sheets (SSS) HS-PS2-1 HS-PS2-2 NGSS Civic Memorial High School - Physics Concept # What we will be learning Mandatory Practice 1 Forces Practice problems 1 2 Newton s 1st Law Practice problems 2 3 Newton s 2nd Law Practice problems 3 4 Newton s 3rd Law Practice problems 4 5 Applying Newton s Laws Practice problems 5

2 --- Newton s Laws unit student success sheets--- Page 2 Concept 1 Concept 2 Concept 3 Concept 4 Concept 5

3 --- Newton s Laws unit student success sheets--- Page 3 #1 Forces Forces are always caused by some and exerted on an. The agent is the thing the pushing or pulling. The is the thing that the pushing or pulling. We classify according to the that exerts the force. We will talk about a few of the ones. Gravity : The force exerted by the that you are on. Your is a measure of the gravitational force that exerts on you. Tension : The force exerted by a, chain, or similar device. Many times tension is accompanied by an. Normal Force : The force exerted by a that an object rests upon. This force is always to the surface. It is sometimes called force. Friction : The force exerted by a surface when it is. This force is l to the surface. You can feel this force when you your or slide them across a surface. Air Resistance : The force exerted by the air that motion through the air.

4 --- Newton s Laws unit student success sheets--- Page 4 Practice Problems 1: A 4.60 kg sled is pulled across a smooth ice surface. The force acting on the sled has a magnitude of 6.20 N and points in a direction 35.0 o above the horizontal. If the sled starts from rest, how fast is it going after being pulled for 1.15 s? To give a 19 kg child a ride, two teenagers pull on a 3.7 kg sled with a rope. Both teenagers pull with a force of 55 N at an angle of 35 o relative to the forward direction. In addition, the snow exerts a retarding force on the sled that points opposite to the direction of motion and has a magnitude of 57 N. Find the acceleration of the sled and child. #2 Newton s 1st Law Newton s first law describes how objects are by. A force is defined as a or a. Force has both and, therefore it has a. An object at rest at rest unless acted upon by an force.

5 --- Newton s Laws unit student success sheets--- Page 5 The net force of an object is the sum of all of the forces acting on it. Net force and force mean the thing and can be. An object will not change it or unless a net force causes it to. In a real life example if you something it eventually but this is due to. In a environment if you push something it will on stopping. Newton s 1st law is sometimes called the law of. The meaning of the word inertia is. Loosely speaking we can say matter is and it doesn t want to it s motion unless forced to do so. The tendency of an object to any change in motion is referred to as it s. Practice problems 2: Is it possible for an object at rest to have one force acting on it? If your answer is yes, provide an example. If your answer is no, explain why not? What is the difference between force and net force?

--- Newton s Laws unit student success sheets--- Page 6 #3 Newton s 2nd Law caused by a force in the form of an equation would be a = F/m Notice that acceleration is to the force and proportional to

6 --- Newton s Laws unit student success sheets--- Page 6 #3 Newton s 2nd Law caused by a force in the form of an equation would be a = F/m Notice that acceleration is to the force and proportional to the. Rearranging this gives us the better known equation. The of acceleration is always the same as the direction of the. We measure force using a unit called. 1 Newton is defined as the force required to give a 1 mass an of 1 m/s 2 Quick Example: An 1800 kg car has an acceleration of 3.8 m/s 2. What is the force acting on the car?

7 --- Newton s Laws unit student success sheets--- Page 7 Newton s 2nd Law applies in a single force and force situation. In general there are forces acting on any given object. The of the forces (the net force) acting on an object is to its mass times its. Practice Problems 3: If the force acting on an object doubles, what happens to the object s acceleration? If the mass of the object doubles, What happens to the object s acceleration? An 1800 kg truck pulls a 620 kg trailer away from a stoplight with an acceleration of 1.16 m/s 2. What is the net force acting on the truck? # 4 Newton s 3rd Law Newton s third law describes the that objects exert on one. Nature produces just force at a time. For example you touch someone without being touched in

8 --- Newton s Laws unit student success sheets--- Page 8 For every force acting on an object there is a force acting on a object. The action and reaction forces are in magnitude and in direction. This is commonly to for every there is an equal and opposite. Action-reaction forces act on objects. As a result the forces do each other out. Since they act on objects they generally produce accelerations. Quick Example: Two groups of canoeists meet in the middle of a lake. After a brief visit a person in canoe 1 pushes on canoe 2 with a force of 46 N to separate the canoes. The mass of canoe 1 and its occupants is m 1 = 150 kg, and the mass of canoe 2 and its occupants is m 2 = 250 kg. What is the acceleration of each canoe? Newton s laws can be to objects. They describe and are called the laws of. For things such as atoms mechanics is used to explain motion. Practice Problems 4: Driving home from school one day, you spot a ball rolling out onto the street. You brake for 1.20 s, slowing your 950 kg car from 16.0 m/s to 9.50 m/s. (a) What was the average force exerted on

9 --- Newton s Laws unit student success sheets--- Page 9 your car during braking? (b) How far did you travel while breaking? Responding to an alarm, a 782 N firefighter slides down a pole to the ground floor, 3.3 m below. The firefighter starts at rest and lands with a speed of 4.4 m/s. Find the average force exerted n the firefighter by the pole. #5 Applying Newton s Laws It is helpful to make showing all the. A sketch showing all the forces acting on an is referred to as a diagram. Weight is a force measured in. Mass is a of the of an object measured in kg. This is why you weigh on the moon, there is less. weight is the way you weight from the force exerted upward on your feet from the. If the floor exerts force than your weight you feel. If the floor exerts force than your weight you feel. Imagine you are in an elevator with forces on you. - (your weight)

--- Newton s Laws unit student success sheets--- Page 10 - The force (Normal Force) W a - W = ma y (The acceleration of the elevator = a y so a = a y ) If a < 0 or the elevator is going, you feel.

10 --- Newton s Laws unit student success sheets--- Page 10 - The force (Normal Force) W a - W = ma y (The acceleration of the elevator = a y so a = a y ) If a < 0 or the elevator is going, you feel. If a = 0 or the elevator is your weight is If a > 0 or the elevator is going you feel. Practice problems 5 On a planet far, far away, an astronaut picks up a rock. The rock has a mass of 5.00 kg, and on this particular planet its weight is 40.0 N. If the astronaut exerts an upward force of N on the rock, what is its acceleration? As part of a physics experiment, you stand on a bathroom scale in an elevator. Though your normal weight is 610 N, the scale reads 730 N. (a) is the acceleration of the elevator at this moment upward, downward, or zero? (b) calculate the magnitude of the elevator s acceleration. (c) What, if anything can you say about the velocity of the elevator? Explain

Review 3: Forces. 1. Which graph best represents the motion of an object in equilibrium? A) B) C) D)

Review 3: Forces. 1. Which graph best represents the motion of an object in equilibrium? A) B) C) D) 1. Which graph best represents the motion of an object in equilibrium? A) B) C) D) 2. A rock is thrown straight up into the air. At the highest point of the rock's path, the magnitude of the net force