Flashcards in CH 4-5-6 Deck (84)

Loading flashcards...

1

## What weighs 1 N?

### an apple

2

## What weighs 10N?

### Large Textbook (a 1 liter bottle of soda)

3

## What weighs 100N?

### 3 Gallons of milk

4

## What weighs 1000N?

### Mr. Nystrom wearing a backpack full of books

5

## If you weigh 600N and are hanging on a rope, you are pulling down 600N on the rope. The rope is pulling ______

### up 600N on you!

6

## If you weigh 600N and jump off of a building, do you accelerate towards the earth? Does the earth accelerate towards you?

### YES, you accelerate toward the earth and YES the earth accelerates toward you (it is hard to see)

7

## How can you think of gravity to help you "see" objects being pulled towards eachother?

### Imagine a bungee between them. A bungee between two cars may pull them both together at the same acceleration, but a bungee between a car and a skateboard will mostly pull the skateboard more. MASS RESISTS ACCELERATION

8

## Why don't you see the earth move when you jump up?

### It is so massive that it barely moves

9

## If force = mass * acceleration, then acceleration =

### FORCE / MASS

10

## if force = mass * acceleration, then mass=

### FORCE / ACCELERATION

11

## When you fire a gun, the force on the bullet is equal to the _____________

### force on the gun

12

## why does a bullet go faster forward than the gun moves backwards if they have the same force?

### the gun has more mass. If you push a roller skate with the same force that you push a bus, the rollerskate will accelerate faster! Mass resists acceleration.

13

## What is a way to think of mass when it comes to movement?

### MASS RESISTS ACCELERATION (this is what we call inertia)

14

## How do you sketch the resultant force of two vectors?

### USE THE PARALELLOGRAM RULE.

15

## What does the delta (the little triangle) symbol mean?

### It means "CHANGE IN"

16

## What is Newton's First Law?

### Object stays at rest, or moves at a constant velocity in a straight line unless a force acts on it.

17

## What is Newton's Second Law?

### F= ma Force increases acceleration, mass resists accelertion

18

## What is Newton's Third Law?

### Every action (force) has an equal and opposite reaction

19

## Give a quick summary of Newton's three laws of motion:

### FIRST: objects in motion or rest stay that way, SECOND: harder to push more massive objects , THIRD: action have equal opposite reactions

20

## What are the three equations from newton's second law? (my fish is from massachusetts)

### a=F/m F= ma F/a = m

21

## If you are given a force and an acceleration, you can find ____ by using the equation ____

### mass, m= F/a

22

## If you are given a mass and an acceleration, you can find ____ by using the equation ____

### Force, F= ma

23

## If you are given a force and a mass, you can find ____ by using the equation ____

### a = F/m

24

## Describe what NET force is

### It is what is left after you combine all the forces (things cancel out).

25

## How can we add two vectors (find resultant) by sketching?

### Use the parallelogram rule, and the DIAGONAL is the resultant vector when both components start from the same spot.

26

## How do we make sure our calculator is in the right mode?

### press MODE> put cursor on DEGREES> press ENTER

27

## What is the net force on an object at rest?

### zero (not accelerating), but has potential energy!

28

## What is the net force on an object moving at a constant velocity? Why?

### zero (not accelerating) but has kinetic energy!

29

## What has to be happening in order for net force to not be zero?

### it must be ACCELERATING (changing velocity). just moving is not enough, it has to be changing speeds!

30