Term
| What is the official statement of newton's 1st Law of Motion? |
|
Definition
| An object at rest remains at rest and an object in motion remains in motion at a constant velocity unless acted upon by an unbalanced object. |
|
|
Term
| Official statement of Newton's 2nd Law of Motion? |
|
Definition
| A body of mass m subject to a force F undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma. Alternatively, the total force applied on a body is equal to the time derivative of linear momentum of the body. |
|
|
Term
|
Definition
| The tendency of objcts to resist a change in motion |
|
|
Term
| How do you determine which object has more inertia? |
|
Definition
| Whichever one has more mass has more inertia. |
|
|
Term
| Would it be easier to push a car on the moon or Earth? |
|
Definition
| It's the same because of you are opposing its inertia. |
|
|
Term
| Would it be easier to lift a car on the moon or Earth? |
|
Definition
| The moon, because you are opposing its weight, and also because there is less gravity. |
|
|
Term
|
Definition
1. The amount of matter in an object.
2. The measurement of an object's inertia. |
|
|
Term
|
Definition
| The force of an object due to gravity. |
|
|
Term
| What are the units of mass and weight? |
|
Definition
| Mass = grams, weight = newtons |
|
|
Term
| Are mass and weight the same thing? |
|
Definition
|
|
Term
| Are mass and weight in any way proportional? |
|
Definition
| Yes, directly proportional. |
|
|
Term
| When can the mass of an intact object change? |
|
Definition
|
|
Term
| Mass and volume are not necessarily proportional. Why? |
|
Definition
|
|
Term
| Newton's second law of motion in equation form. What happens to acceleration if you change mass or the net force by a certain amount? What three forms can this equation be written in? |
|
Definition
| 1. Acceleration = net force/mass 2. Acceleration and Force are directly proportional, Acceleration and Mass are inversely proportional 3. Acceleration is in the direction of the net force. |
|
|
Term
|
Definition
| Add forces in one direction and subtract smaller from larger. |
|
|
Term
| Is force a vector or scalar quantity? Why? |
|
Definition
| Vector because it involves both direction and magnitude |
|
|
Term
| What is the normal force? |
|
Definition
| A force produced by a surface an object is resting on, created by the atoms in the surface (atoms are like tiny springs) |
|
|
Term
| Direction of acceleration based on the net force |
|
Definition
| A is in the direction of the NF |
|
|
Term
| What does the magnitude of the friction force depend on? |
|
Definition
| Weight, materials that are made of (NOT SURFACE AREA) |
|
|
Term
|
Definition
|
|
Term
| Can an object in motion be in equilibrium? Explain. |
|
Definition
| Yes, if it's at a constant velocity. (dynamic equilibrium) |
|
|
Term
| How much force must you exert to slide a box over a floor at constant velocity? |
|
Definition
| Friction force is equal and opposite |
|
|
Term
| Official statement of newton's 3rd law of motion. |
|
Definition
| (see notes) For every action, there is an there is a reaction. This reaction force is equal and opposite to the action force |
|
|
Term
| What are the two force in Newton's 3rd law called? |
|
Definition
|
|
Term
| Describe the timing of the two forces in Newton's 3rd Law of Motion. |
|
Definition
|
|
Term
| Check your understanding:While driving down the road, a firefly strikes the windshield of a bus and makes a quite obvious mess in front of the face of the driver. This is a clear case of Newton's third law of motion. The firefly hit the bus and the bus hits the firefly. Which of the two forces is greater: the force on the firefly or the force on the bus? |
|
Definition
| Trick Question! Each force is the same size. For every action, there is an equal ... (equal!). The fact that the firefly splatters only means that with its smaller mass, it is less able to withstand the larger acceleration resulting from the interaction. Besides, fireflies have guts and bug guts have a tendency to be splatterable. Windshields don't have guts. There you have it. |
|
|
Term
| Check your understanding:Many people are familiar with the fact that a rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases that expand outward allowing the rifle to push forward on the bullet. Consistent with Newton's third law of motion, the bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is ... a. greater than the acceleration of the bullet. b. smaller than the acceleration of the bullet. c. the same size as the acceleration of the bullet. |
|
Definition
| The force on the rifle equals the force on the bullet. Yet, acceleration depends on both force and mass. The bullet has a greater acceleration due to the fact that it has a smaller mass. Remember: acceleration and mass are inversely proportional. |
|
|
Term
| The forces described in Newton's 3rd Law of Motion always act in... |
|
Definition
|
|
Term
| Example of a skydiver falling to the Earth or a rifle firing a bullet. Compare the force each exerts on the other. Which will accelerate more and why? |
|
Definition
| The force exerted is the same, the one with smaller mass accelerates more (skydiver, buller) |
|
|
Term
| How must one decide which force is the action force and which force is the reaction force? |
|
Definition
| It doesn't matter which is which |
|
|
Term
| Does the action force act on the same object as the reaction force? |
|
Definition
|
|
Term
| Is momentum associated with objects in motion, objects at rest, or both? |
|
Definition
|
|
Term
| What is the equation for momentum when direction matters, and when direction doesn't matter? |
|
Definition
Momentum=mass x velocity
OR
Momentum= mass x speed |
|
|
Term
| Momentum changes when ______ or _______ changes. |
|
Definition
|
|
Term
| What is required to change momentum? |
|
Definition
|
|
Term
| The amount momentum changes is based on the _______ |
|
Definition
|
|
Term
| What is the equation for impulse? |
|
Definition
|
|
Term
| Brick wall vs. Haystack situation. Be able to explain this situation in depth! |
|
Definition
| The change in momentum is the same in both cases, therefore, the impulse is the same in both cases. For haystack, time of impact is greater so the force is less. For brick, time of impact is less so the force of impact is rgeater. |
|
|
Term
| Provide two reasons why it is clear momentum and inertia are not the same thing. |
|
Definition
1. Momentum depends on mass and velocity, while inertia depends on just mass.
2. Momentum is only for onjects in motion and inertia is for objects in motion and at rest. |
|
|
Term
| What type of force is required to change momentum? |
|
Definition
| unbalanced, external force |
|
|
