Ch4_Ordover

Lesson 1 (a-d)
A1) What is Newton's first law? It is the law of inertia. It says that objects tend to keep doing what they are doing unless acted upon by an unbalanced force. Thus, objects at rest stay at rest and objects in motion stay at constant speed and direction unless acted on by an unbalanced force. A2) What applications does this have? This can be seen when a car is braking. The car is being acted on by an unbalanced force from the brakes but the person in the car is not being acted on by an unbalanced force, so they keep moving forwards.

B1) What is inertia and how is it related to mass? It is the resistance an object has of changing its state of motion. Mass is dependent on inertia. A larger object has more resistance to change its state of motion. Thus, more mass means more inertia and vice versa. B2) What did Galileo contribute to this idea? Galileo reasoned that friction eventually stopped motion. He created the idea of inertia and Newton built on it.

C1) What does state of motion mean? An object's state of motion is defined by its velocity. Thus inertia is the tendency of an object to resist changes in velocity or to resist acceleration.

D1) What is the difference between balanced and unbalanced forces? When there are opposite forces that are of equal magnitude. When forces are balanced there is not acceleration. In an unbalanced force, forces in the opposite direction are of different magnitude. This causes acceleration and a change of state of motion.

Lesson 2 (a-d)
A1) What is the meaning of force and what kinds of forces are there? A force is a push or a pull on an object that is the result of an interaction with another object. Forces can either be contact forces or forces from action-at-a-distance. Contact forces result from two objects physically pushing or pulling each other like friction, tension, normal, etc. Forces using action-at-distance exert a push or a pull without physically touching the object like gravity.

B1) What are the types of forces? Applied force- force applied to an object by another person or object Gravitational force- the force in which large objects, mainly planets and stars, attract other objects to themselves Normal force- support force exerted on an object that is in contact with another stable object Friction force- force exerted on an object that moves or tries to move across a surface Air Resistance- force that acts on objects as they travel through the air Tension force- force that is transmitted through a string/rope/cable when it is pulled tight by forces acting on opposite ends Spring Force- force exerted by a compressed or stretched spring to an object attached to it B2) What is the difference between mass and weight? Weight takes gravity into account, while mass is just the amount of matter.

C1) How do you draw a free body diagram? A free body diagram shows magnitude and direction of all the forces acting on an object. Length of the arrow shows magnitude while direction of the arrow shows direction of the force. The arrows are labeled with their force.

D1) How do you determine net force? You find it by adding up all the individual vectors. Thus, it is the vector sum of all the forces. If forces are balanced then net force is zero. If there are any unbalanced forces than net force will not be zero and it will cause acceleration.

Lesson 3 (a-b)
A1) What is Newton's Second Law? The acceleration of an object is dependent inversely on the mass of the object and the net force being exerted on it. If net force is increased, so if acceleration. If mass is increased, acceleration is decreased. The equation is: a=∑F/m or ∑F=m*a.

B1) What is the big misconception about Newton's Laws? The misconception is that force needs to continually be applied to something for it to stay in motion. If you take friction and air resistance away an object will continue moving until another force is exerted on it. A net force causes acceleration in the same direction as the net force.