Flashcards in Unit 3 Deck (52)

Loading flashcards...

1

## impulse is equal to...

### ...change in momentum

2

## What do you need in order to cause a change in momentum?

### Have to exert an impulse.

3

## Impulse equation

###
impulse = force * time interval = Ft

Ft = change in momentum = (change in m*v)

4

## Momentum equation

### Momentum = mass * velocity = mv OR mass * speed

5

## Momentum

### Inertia in motion

6

## A moving object can have a large momentum if it...

### ...has a large mass, a high speed, or both.

7

## What produces acceleration?

### Force.

8

## Impulse

### Change in momentum depends on the force that acts the length of time it acts.

9

## Decrease momentum

### Extend the time of contact, reduce the force of the catch.

10

## The impulse required to bring an object to a stop and then to "throw it back again" is...

### ...greater than the impulse required merely to bring the object to a stop.

11

## Law of Conservation of Momentum

### States that, in the absence of an external force, the momentum of a system remains unchanged.

12

## Whenever objects collide in the absence of external forces...

### ...the net momentum of both objects before the collision equals the net momentum of both objects after the collision.

13

## Elastic collision

### When objects collide without being permanently deformed and without generating heat.

14

## Inelastic collision

### A collision in which the colliding objects become distorted and generate heat during the collision.

15

## Equation conservation of momentum

###
net momentum(before collision) = net momentum(after collision)

OR

(net mv)before = (net mv)after

16

## Vector sum of momenta is...

### ...the same before and after a collision

17

## The force or impulse must be exerted on the object by something....

### ...outside the object.

18

## Momentum is conserved only when interacting objects move along...

### ...the same straight path

19

## With the absence of air resistance in space...

### gravity is the only opposing force that affects two docking space stations.

20

## Properties of energy

###
-is conserved

-cannot be created or destroyed

-can change form

-measured in joules

21

## Work

### Product of a net force on an object and the distance through which the object is moved.

22

## Power

### Rate at which work is done.

23

## Power equation

###
(work done)/(time interval)

Measured in watts.

24

## Mechanical energy

### Energy due to the position or the movement of something. Kinetic and potential energy

25

## Potential energy

### (PE). In stored state it has the potential for doing work. Three examples: elastic potential, chemical, and gravitational potential.

26

## Kinetic energy

### energy of motion. Not moving: zero units of energy.

27

## Energy

### Property of an object on system that enables it to do work. Measured in joules

28

## Work is done when...

### a force acts on an object that results in the object moving in direction of the force.

29

## Work equation

###
work = net force * distance

W = Fd

30