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Flashcards in Unit 3 Deck (52)
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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

1 joule =

1N/1m