luoa 8th grade science test 3

How much work is done using a 120-watt light bulb for one hour?

432,000 joules

If the mechanical advantage of a pulley is four and you want to raise a 120 cm object off the ground, how far do you have to pull the rope?

480 cm

If the IMA of a wheel and axle is 12 and the Fe is 48 Newtons, what is the force of resistance?

576N

Who invented a very efficient lubricating device for trains?

Elijah McCoy

Work = _________________X_____________________.

Force, Distance

A wheel with a series of teeth around the perimeter is called a/an ___________.

gear

Today we use the term "horsepower" to refer to the power of ___.

motors in general

You are not accomplishing any work, in physics, unless something __________.

moves

You just walked up the tallest mountain in the US and are sitting down at the top. How much work are you doing?

none

The rate at which work is being done or energy transformed is called _________.

power

God expects us to follow His example by finishing our work and then __________.

resting

What type of triangle did you make to create an inclined plane to transform into a example of a screw?

right

What simple machine is more commonly used more than any other?

screw

The term "horsepower" helped people understand the transition from animal power to ___ power.

steam

The towers of a suspension bridge can handle the tension put on them because ___.

they are anchored on bedrock.

The tall parts of a bridge that support the long wire cables are the _________.

towers

What two parts of a suspension bridge resist the weight of the load on the bridge?

towers and anchors

What do we call the unit of power equal to one joule per second?

watt

What is used to measure power and equals one joule per second?

watt

A simple machine that combines two inclined planes and is used to split objects is called a __________.

wedge

A hand-operated machine that combines gears with a crank and chain or cable is called a/an __________.

winch

When a machine exerts a force over a distance, it is doing __________.

work

___________ is the force placed on an object times the distance in the direction the object is moved.

work

What do scientists use to determine the efficiency of a machine?

work output/ work input X 100

Many scientists believed the laws they were discovering were designed by ____________.

God

If a 15-foot see-saw had a child weighing 100 pounds on the side where the seat was 10 feet away from the fulcrum and the child on the opposite side weighed 200 pounds and was 5 feet from the fulcrum, which formula would be correct to figure out if they were in static equilibrium?

(100lbs.) (10ft.) = (200lbs.) (5ft.)

A weightlifter exerted a force of 8,000 newtons on a car that needed to be moved, but he was unable to budge it. How much work was done?

0

Taylor's car broke down and he exerted a force of 8,000 newtons trying to push it before giving up and calling the tow truck. How much work did he accomplish?

0

A force of 100 newtons was necessary to lift a rock. A total of 150 joules of work was done. How far was the rock lifted?

1.5m

If you are pushing a shopping cart full of scrap wood using a force of 35 newtons a distance of 40 meters in 10 seconds, how much power are you using?

140 watts

If a stone weighs 112 Newtons, what force must be applied to the rope used when the mechanical advantage of the pulley is eight?

14N

A couch is being lifted to your second story apartment. It weighs 1,000 newtons. It is lifted up 9 meters in 60 seconds. How much power was used?

150 watts

What is the power of a kitchen mixer if it can perform 4,750 joules of work in 25 seconds?

190 watts

If it took 40 joules to push a cart 2 meters across the floor. With what force was the cart pushed?

20N

The wheel barrel is an example of what kind lever?

2nd class lever

An apple weighing 1.0 newton is lifted 3 meters. How much work has been done?

3 joules

James used 600 newtons of force to push a car 5 meters. How much work did he do?

3,000 joules

Amelia uses a force of 18 newtons to push her wagon a distance of 2 meters. How much work did she do?

36 joules

A ramp is 8 meters long and I need to use it to raise up a box 2 meters. The box weighs 300 newtons. How much force are you going to need to exert to get the box up the ramp?

75N

How much work is done pushing a shopping cart 100 meters with a force of 88N?

8800 joules

How much work is done by using a 400-watt microwave oven for 4 minutes?

96,000 joules

Wheel and Axle

A simple machine that consists of two attached circular or cylindrical objects that rotate about a common axis, each one with a different radius.

Fixed Pulley

A simple machine that is attached to a surface and uses a stationary grooved wheel through which a rope, belt, chain, etc. runs.

___________ is the key, especially for suspension bridges.

Balance

The longest over water bridge in the world was built in which country?

China

Which of these formulas is correct for calculating ideal mechanical advantage?

IMA = Force of resistance / Force of effort

The period of rapid industrial growth that began in England during the middle of the eighteenth century and then spread over the next fifty years characterized by the replacement of hand tools with power-driven machines is called the ____________.

Industrial Revolution

What scientist's experiments led him to discover the Law of Conservation of Energy and the First Law of Thermodynamics resulting in the unit of energy in the metric system being named after him?

James Prescott Joule

What is the unit called that we will use to measure work?

Joule

What is Psalms 90:17?

Let the favor of the Lord our God be upon us, and establish the work of our hands upon us; yes, establish the work of our hands!

What measurement do we use to determine the amount of force used to move an object by a simple machine?

Newtons

Thomas Telford changed three things about the ancient suspension bridge design to create the modern design. Use at least three complete sentences to explain one of those changes. Remember to use proper grammar and mechanics when writing you sentences.

One thing Thomas added was hangers to the bridge to disperse even more weight. Another thing he added was driving 18 meters into the ground to strongly anchor his anchors. These are two changes that have made the bridges that still stand today.

In a simple machine, the weight of the object being moved is called the _________.

Output force

The formula for power is ________.

Power = Work / Time

What was Adam's first job?

Taking care of Eden.

Name one arch today that can be seen in nature.

The Natural Bridge in Southwestern Virginia.

If a construction engineer was hired to design and build a bridge over a high gorge with a river people use for white water rafting, should he choose an arch or suspension bridge? Explain your answer in three to five sentences. Remember to use proper grammar and mechanics when writing your sentences.

The engineer should use an arch bridge so that the people going under the bridge have nothing of a pillar to run into. If a suspension bridge was built would have to maneuver around the pillar and the pillar could not be strong foundational in the water moving around it. Overall, an arch bridge would be better.

Rake Shovel Hammer Fishing pole Broom Jawbone Baseball bat are examples of what kind of lever?

Third class lever

movable pulley

a pulley that free to move up and down

Your [answer] is a body part that is a lever.

arm

A bridge that is made of two or more self-supporting sections attached to each other with short sections is called a/an ___.

cantilever bridge

block and tackle

combines multiple fixed and moveable pulleys

Many anchors for bridges are made from reinforced ___ slabs larger than a building.

concrete

The part of a bridge a vehicle drives on is the _________.

deck

The only force that counts is the force you use in the _______ you are moving.

direction

People use an inclined plane to exert less force over a greater _________.

distance

The size and shape of the original inclined plane determines the ____________ between the threads of the screw.

distance

The force applied to a machine in order for work to be done is called the ________ force.

effort

The ability to do work is called _______.

energy

What is called "the ability to work?"

energy

To use unfairly for one's own advantage is ___________.

exploitation

The wheel and axle is an example of a/an _________.

first class lever

The force that resists motion when using a screw that keeps it in place is called ___________.

friction

When finding the ideal mechanical advantage (IMA), the negative force not being included is ____________.

friction

A first-class lever always has the ________ between the side holding the load and the side where the effort is being applied.

fulcrum

On a first-class lever, the area that pivots to lift the load is called the __________.

fulcrum

A common unit of power equal to about 746 watts is called ___________.

horsepower

The field of science that deals with the practical application of liquid in motion is called __________.

hydraulics

IMA stands for _________________.

ideal mechanical advantage

What do we call a simple machine that is a flat surface set at an upward angle sloping at any point less than a 90 degree angle?

inclined angle

A person who manages or owns an industry is called a/an _________.

industrialist

What is the amount of strength that is applied to the rope in a pulley to raise the object called?

input force

A screw ______ is a heavy-duty cylinder with a screw mechanism in it that is turned by a lever to multiply its mechanical advantage hundreds of times.

jack

What do we call a unit of work or energy equal to the work done by a force of one newton acting through a distance of one meter?

joule

What are the two main categories of simple machines?

levers, inclined planes

In a first-class lever, the effort arm is _________ than the load arm.

longer

What do we call devices that help make work easier?

machines

What do we call the number that tells how many times a machine multiplies a force?

mechanical advantage

What is the factor by which a simple machine multiplies the strength put into a machine called?

mechanical advantage

The amount of work a machine can do because of an object's kinetic and potential energy is called ___________.

mechanical energy