Unit 4 Physics

A piece of putty moving with 2 units of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both are set in motion with a combined momentum that is __ _____

2 units

The SI unit of work is ____

J

______ energy is the energy due to the positionof something or the movement of something.

Mechanical

A piece of putty and a rubber ball have the same mass. If you drop them from the same height, which object will produce a greater impulse and why?

Rubber ball, bounces

If the momentum of an object changes and its mass remains constant, it is _____

accelerating

Adding multiple pulleys makes a ____ and ____ system

block, tackle

If your Force is limited, how can you MAXIMIZE the impulse you apply?

by increasing the time of contact

If your change in momentum is constant, how can you MINIMIZE the force applied to you?

by increasing the time of contact

Internal forces come in balanced pairs that _____ within the system

cancel

What are the types of non-mechanical energy?

chemical, nuclear, thermal, electromagnetic

A see-saw at a playground is an example of a ______

class 1 lever

In an isolated system, the total linear momentum is always _____

conserved

In elastic collisions, momentum and energy are ______

conserved

In inelastic collisions, energy is lost to heat or other forms, but momentum is still ______

conserved

When any quantity in physics does not change, we say it is _____

conserved

The total energy in the universe is _____

constant

You an MINIMIZE the force of impact by maximizing the time of ____

contact

Increasing the time of contact will _____ the force of impact

decrease

machines increase output force, and _____ output distance

decrease

A collision is considered elastic if there is no lasting _____

deformation

Wedges and Screws; IMA= ____/_____

depth/ thickness

For an inclined plane a small input force turns into a large output force by spreading it out over a greater _____

distance

A freight train rolls along a track with considerable momentum. If it were to roll at the same speed but had twice as much mass, its momentum would be ____

double

The ratio of useful work output to the total work input is called the ______

efficiency

What is in the middle of a 3rd class lever?

effort

The side of the fulcrum that you push on is called the _____ ______

effort arm

IMA= _____/_____

effort arm/ resistance arm

An _____ collision is when objects collide or rebound without lasting deformation or generation of heat

elastic

Perfectly _____ collisions are not common in the everyday world

elastic

_______ _____ energy is where an object that is stretched will go back to the original shape

elastic potential

Work equals the change in _____

energy

Work involves a transfer of _____ between something and its surroundings

energy

_____ is the ability to do work or cause change

energy

Energy (before) = ______

energy (after)

% _____ _____= (EPE-KE)/EPE x 100

energy lost

The property of an object or system that enables it to do work is ____. Like work, energy is measured in _____

energy, joules

All simple machines ideally work on the principle that work input ____ work output

equals

The momentum of a system cannot change unless it is acted on by _____ forces

external

______ forces are forces that act on a system from outside

external

Inclined planes multiply and redirect ____

force

Machines result in a multiplicationof a _____

force

To increase the momentum of an object, apply the greatest _____ possible for as long as possible

force

When you extend the time, you reduce the ____

force

All levers contain a _____ that they pivot on

fulcrum

What is in the middle of a 1st class lever?

fulcrum

_____ ______ energy is energy that is a result of an objects position or condition

gravitational potential

The impulse required to bring an object to a stop and then to throw it back again is _______ than the impulse required merely to bring the object to a stop

greater

If Newton doubles the length of her wrench, she will need ____ the force to unscrew a struck bolt.

half

A truck at rest has/has no momentum at all.

has no

A force applied over a period of time is called an _____

impulse

No net force means there is no net _____ and thus no change in momentum

impulse

Since ∆p is greater in bouncing situations, the ______ applied will be greater!

impulse

The momentum change of an object is equal to the _____ acting on it

impulse

______ is a change in momentum

impulse

Wedges and screws are a modified ________ _______

inclined plane

In _____ collisions, objects collide and become distorted or generate heat.

inelastic

______ forces are forces that act within a system

internal

If the momentum of an object changes and its mass remains constant, there is/is not a force acting on it

is

If a system is not affected by any net external force, it is said to be _____

isolated

What are the SI units of momentum?

kg·m/s

_____ energy is energy of moving things

kinetic

The two types of mechanical energy are _____ energy and _____ energy

kinetic, potential

If the change in momentum occurs over a short time, the force of impact is _____.

large

a small force applied over a large distance yields a _____ force over a _____ distance

large, small

Inclined plane; IMA= _____/_____

length,height

The work out is always _____ than the work in.

less

A ball is thrown into the air with 100 J of kinetic energy, which is transformed into gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is _____

less than 100 J

SIMPLE MACHINES allow us to do the same job with _____ FORCE, but using ____ ENERGY

less, more

The amount of potential energy possessed by an elevated object is equal to the work done ______ it

lifting

What is in the middle of a 2nd class lever?

load

A cannon recoils from launching a cannonball. The speed of the cannon's recoil is small because the cannon has far more ____ than the cannonball

mass

A moving truck has more momentum than a car moving at the same speed because the truck has more _____

mass

GPE depends on _____ and _____ above the ground

mass, height

KE depends on the ____ and _____ of the object in motion

mass, speed

When energy is lost as heat, it cannot be transformed back to _____ energy

mechanical

A block and tackle system will give an even higher ______ _______

mechanical advantage

What are the two kinds of energy?

mechanical and non-mechanical

If an object has kinetic energy, then it must also have ______

momentum

The ______ of a body is equal to the product of its mass and its velocity

momentum

The concept of inertia in motion is called ______

momentum

When a net force acts upon a body for a period of time, the Impulse applied by the force is equal to the body's change in ______

momentum

A single _____ pulley allows the input force on the right only to support half the weight

movable

The single ____ pulley allows the output force to share the 2 sections of rope pulling upward

movable

When the force applied and the motion are in opposite directions, ______ work is done

negative

Momentum of a system is conserved only when there is no _____ _____ force acting on the system

net external

Work is done when a ___ ___ causes motion

net force

Work is done when a net force acts on an object and the object moves in the direction of the ____ ______

net force

Net momentum (before) = ________

net momentum (after)

What are the SI units of impulse?

n·s

AMA= _______ / ______

output force, input force

Work done on an object divided by the time taken to do the work is called _____

power

Wheel and axle; IMA= _____/_____

radius wheel/ radius axle

Wedges and screws allow for the _____ to be pushed rather than some other object

ramp

The side of the fulcrum that the load is on is called the _____ ______

resistance arm

A karate expert executes a swift blow and splits a cement block with her bare hand. The times of impact on both the block and the expert's hand are the ____

same

A karate expert executes a swift blow and splits a cement block with her bare hand. The forces on both the block and the expert's hand have the _____ ______

same magnitude

A karate expert executes a swift blow and splits a cement block with her bare hand. The impulses on both the block and the expert's hand have the ____ _____

same magnitude

A ____ is an inclined plane Wrapped around a cylinder

screw

A collision is considered elastic if after the collision, the objects have the same ____ as before the collision

shape

What are the two types of pulleys?

single fixed/movable

The spring constant "k" (N/m) is the ____ of the graph Force vs. Stretch

slope

If the change in momentum occurs over a long time, the force of impact is ______

small

A meteor that originally was heading south breaks up into two chunks. One of the chunks moves southwest. The second chunk was not found, but can be guessed that it went _____

southeast

Work is done to change the _____ of an object

speed

Kinetic energy depends on speed ____

squared

A collision is considered elastic if the objects don't _____ _______

stick together

Pulleys; IMA= #_____ supporting the load

strands

A tennis ball launcher is fired. Compared to the impulse on the ball, the impulse one the launcher is ________

the same

Friction Turns Mechanical into _____ Energy

thermal

Suppose a girl is standing on a pond where there is no friction between her feet and the ice. In order to get off the ice, she can ____________

throw something in the direction opposite to the way she wants to go

The reason padded dashboards are used in cars is that they increase the ____ of _____ in a collision

time, impact

In order to catch a ball, a baseball player moves his or her hand backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because the ____ of impact is _____

time, increased

When the wheel is turned the axle _____

turns

Momentum is a ____ quantity

vector

If the momentum of an object changes and its mass remains constant, its _____ is changing

velocity

A collision is considered elastic if the objects that collide don't get ______

warmer

What is the SI unit of power?

watts

A _____ is just two inclined planes, back-to-back

wedge

A key is an example of a _______

wheel and axle

Screwdrivers and cranks are common ________ machines

wheel and axle

Energy is the ability to do ____

work

Power is the RATE at which _____ is done

work

_____ is a quantity that measures the effects of a force acting over a distance

work

_____ is the product of the force on an object and the distance through which the object is moved

work

Efficiency= ______/______

work out, work in