Lesson | Unit D_Sci8 - sts 4.1 - 4.2 | evaluate the design and function and develop and apply a set of criteria

Multiple Choice

What is a machine?

• A) A device that helps us do work or perform a task

• B) A type of animal

• C) A kind of food

• D) A musical instrument

Multiple Choice

A machine can be as simple as a ______.

• computer

• ramp

• car

• smartphone

Multiple Choice

Which of the following are considered simple machines?

• The inclined plane and the lever

• The computer and the smartphone

• The car and the bicycle

• The refrigerator and the oven.

Multiple Choice

What is the term used for the energy added to a machine?

• Energy output

• Energy input

• Energy conversion

• Energy loss

Multiple Choice

Fill in the blank: Machines convert energy input to a different form of energy called ______.

• energy loss

• energy output

• energy waste

• energy storage

Multiple Choice

Why do we use machines to convert energy?

• To increase energy input

• To create energy

• To obtain useful energy output for work

• To reduce energy consumption

Multiple Choice

When a machine transforms energy, some energy will always be lost as which of the following?

• Heat

• Sound

• Light

• All of the above

Multiple Choice

Friction is usually the force that causes the loss of energy. True or False?

• True

• False

Multiple Choice

When a machine transforms energy, some energy will always be lost as ______.

• Heat

• Sound

• Light

• Wobbly wheels (unnecessary movement)

Multiple Choice

What is the relationship between useful energy input and useful energy output?

• A) They are always equal

• B) Input is always greater than output

• C) Output is always greater than input

• D) Input is never equal to output.

Multiple Choice

A perfect machine, which is 100% efficient in converting energy, ________.

• exists

• does not exist

• sometimes exists

• always exists

Multiple Choice

Which of the following statements is true?

• A) A perfect machine is possible

• B) Useful energy input is always equal to useful energy output

• C) A perfect machine does not exist

• D) Energy output is always greater than energy input.

Multiple Choice

What is the definition of efficiency in the context of machines?

• A) The ability to produce maximum output

• B) A measurement of how effectively a machine converts input energy into useful energy output

• C) The speed at which a machine operates

• D) The cost-effectiveness of a machine.

Multiple Choice

Fill in the blank: The efficiency of a machine tells you how much of the energy you gave to the machine is actually transferred to the _______.

• environment

• load

• waste

• system

Multiple Choice

What is the formula for calculating percent efficiency?

• (total work input / total work output) x 100%

• (total work output / total work input) x 100%

• (total energy input / total energy output) x 100%

• (total energy output / total energy input) x 100%

Multiple Choice

What is the efficiency percentage if you earned $$100 and spent$$ 20?

• 70%

• 80%

• 90%

• 100%

Multiple Choice

If you earned $$100 and spent$$ 20, you have $80 remaining. This means you were ___% efficient with your money.

• A) 70

• B) 80

• C) 90

• D) 100

Multiple Choice

According to the analogy, 100% efficiency would mean:

• A) Spending all your money

• B) Saving all your money

• C) Spending half your money

• D) Spending none of your money

Multiple Choice

What does 100% efficiency mean in terms of energy usage?

• All energy is used for useful motion

• Some energy is wasted

• Energy is conserved

• Energy is lost

Multiple Choice

Fill in the blank: Friction always finds a way to ______ some of the energy.

• A) conserve

• B) waste

• C) enhance

• D) store

Multiple Choice

Why is 100% efficiency impossible in machines?

• A) Machines are perfectly designed

• B) Friction always wastes some energy

• C) Energy is always conserved

• D) Machines use all energy for motion.

Multiple Choice

What is one way to reduce friction according to the text?

• Increase surface area

• Use lubricants

• Add more weight

• Increase speed

Multiple Choice

Fill in the blank: Lubricants reduce the surface area where parts rub ______ together.

• apart

• closely

• loosely

• tightly

Multiple Choice

According to the text, what does friction do to useful energy?

• Enhances it

• Steals it

• Multiplies it

• Stores it

Multiple Choice

Which of the following activities uses rosin to improve grip?

• Cycling

• Baseball

• Swimming

• Running

Multiple Choice

In curling, sweepers sometimes stop sweeping to ______ friction and slow down the rock.

• increase

• decrease

• eliminate

• maintain

Multiple Choice

What is the purpose of sweeping the ice in front of the rock in curling?

• To increase friction

• To decrease friction

• To maintain friction

• To eliminate friction

Multiple Choice

What is the purpose of using large rear tires on a vehicle?

• To minimize friction

• To maximize friction where thrust is created

• To reduce weight

• To increase speed

Multiple Choice

Fill in the blank: Small front tires are used to _______ friction in the front, allowing more energy to be used for acceleration.

• maximize

• minimize

• maintain

• ignore

Multiple Choice

How does reducing friction where it is not needed affect a vehicle's efficiency?

• It decreases efficiency

• It has no effect

• It maximizes efficiency

• It increases weight.

Multiple Choice

What is the efficiency of a ramp if you do 222 J of work and the ramp does 200 J of work?

• 80%

• 85%

• 90%

• 95%

Multiple Choice

If a ramp requires only 200 J of energy, why do you have to apply 222 J? What is the extra 22 J used for?

• Friction

• Sound

• Light

• Heat

Multiple Choice

Fill in the blank: The efficiency of a machine is calculated as (Work done by machine / Work done to make the machine operate) x 100%. If the work done by the machine is 200 J and the work done to make the machine operate is 222 J, the efficiency is ___%.

• A) 80

• B) 85

• C) 90

• D) 95

Multiple Choice

What is a force described as?

• A) A push

• B) A pull

• C) Both A and B

• D) Neither A nor B

Multiple Choice

Force is measured in ______.

• Joules

• Newtons

• Watts

• Pascals

Multiple Choice

What is the symbol for force?

• J

• N

• W

• P

Multiple Choice

What is energy defined as?

• The ability to do work or cause a change in the direction of an object

• The ability to rest

• The ability to consume resources

• The ability to create matter.

Multiple Choice

Kinetic Energy is when ______ is actually being done.

• Rest

• Work

• Consumption

• Creation

Multiple Choice

The amount of kinetic energy or potential energy is measured in ______.

• Watts

• Joules

• Calories

• Volts

Multiple Choice

What type of energy does a ball have when it is held at a height?

• Kinetic Energy

• Potential Energy

• Thermal Energy

• Electrical Energy

Multiple Choice

A cyclist at the top of a hill has ______ energy.

• Kinetic

• Potential

• Thermal

• Sound

Multiple Choice

When a cyclist goes down a hill, what type of energy is primarily being converted?

• Potential to Kinetic

• Kinetic to Potential

• Thermal to Kinetic

• Electrical to Potential

Multiple Choice

What type of energy is described as 'Stored Energy'?

• Kinetic Energy

• Potential Energy

• Thermal Energy

• Electrical Energy

Multiple Choice

Fill in the blank: Kinetic Energy is _______ Energy.

• Stored

• Activated

• Potential

• Chemical

Multiple Choice

Which of the following statements is true?

• A) Potential Energy is Activated Energy

• B) Kinetic Energy is Stored Energy

• C) Potential Energy is Stored Energy

• D) Kinetic Energy is Chemical Energy.

Multiple Choice

What is the ability to do work called?

• Force

• Energy

• Distance

• Power

Multiple Choice

Fill in the blank: Work is a force applied over a ______.

• A) Time

• B) Distance

• C) Speed

• D) Mass

Multiple Choice

Which of the following is a type of energy?

• Kinetic Energy

• Thermal Energy

• Potential Energy

• All of the above.

Multiple Choice

What is work defined as in the context of energy?

• A form of energy

• A transfer of energy

• A loss of energy

• A storage of energy.

Multiple Choice

Machines help people do things that they normally couldn’t do on their own.

• True

• False

Multiple Choice

In the example of the bicycle, your energy is transferred to the pedals giving them ______ energy.

• Potential

• Thermal

• Kinetic

• Chemical

Multiple Choice

What must be true for work to be done according to the image?

• A) Force and motion must be in the same direction.

• B) Force and motion must be in opposite directions.

• C) Only force is needed.

• D) Only motion is needed.

Multiple Choice

In the example given, lifting a 2.0 kg wheel of cheese from the ground to the top of a table, is work done?

• Yes, because the direction of the displacement is the same as the direction of the applied force.

• No, because the force is not applied.

• Yes, because the cheese is heavy.

• No, because the table is too high.

Multiple Choice

Fill in the blank: For work to be done, the force and the ______ must be in the same direction.

• speed

• motion

• weight

• height

Multiple Choice

What is the work done when you push against a wall with a force of 130 N for 10.0 s and the wall does not move?

• 1300 J

• 0 J

• 130 J

• 13 J

Multiple Choice

When carrying a 2.0 kg wheel of cheese 12.0 m across the room, the force applied to hold the cheese up is vertical, and the cheese only moves horizontally. What is the work done by the vertical force?

• 24 J

• 0 J

• 2 J

• 12 J

Multiple Choice

Fill in the blank: The directions of the force applied to hold the cheese up and the movement of the cheese are ________.

• A) parallel

• B) perpendicular

• C) opposite

• D) the same

Multiple Choice

What is Mechanical Advantage?

• A measure of speed

• A machine increasing the force you give it

• A type of energy

• A method of transportation

Multiple Choice

Fill in the blank: The larger the Mechanical Advantage, the greater the machine will ______ your force.

• reduce

• magnify

• ignore

• balance

Multiple Choice

What is the formula for Mechanical Advantage?

• Load Force / Effort Force

• Effort Force / Load Force

• Load Force + Effort Force

• Load Force - Effort Force

Multiple Choice

What is the mechanical advantage (MA) if the load force is 2500 N and the effort force is 500 N?

• 2

• 3

• 4

• 5

Multiple Choice

Fill in the blank: The mechanical advantage (MA) is calculated by dividing the load force by the ________ force.

• Effort

• Load

• Friction

• Gravity

Multiple Choice

If a lever magnifies your force 5 times, what is the mechanical advantage?

• A) 2

• B) 3

• C) 4

• D) 5

Multiple Choice

What is the mechanical advantage (M.A) if the effort distance is 100 cm and the load distance is 50 cm?

• 1

• 2

• 3

• 4

Multiple Choice

If the effort distance is 1000 cm, then what is the M.A?

• 1

• 2

• 10

• 20

Multiple Choice

If a box weighs 40 pounds, how much mass would you need on the other end to lift it with a 100 cm effort arm? Fill in the blank: You would need ___ pounds.

• 20

• 40

• 80

• 100

Multiple Choice

What is the formula for Mechanical Advantage in terms of force?

• Load Force / Effort Force

• Effort Force / Load Force

• Load Force + Effort Force

• Load Force - Effort Force

Multiple Select

Mechanical Advantage can be ____.

• 1 (No Advantage)

• less than 1 (converts into less force)

• greater than 1 (magnifies your force)

Multiple Choice

Why does Mechanical Advantage have no units?

• Because it is a ratio

• Because it is a force

• Because it is a length

• Because it is a mass.

Multiple Choice

What is the main trade-off when using a machine like a lever?

• Speed for accuracy

• Force for distance

• Time for energy

• Power for efficiency

Multiple Choice

Fill in the blank: The greater the force generated, the greater the ______ the machine makes you move.

• A) speed

• B) distance

• C) time

• D) power

Multiple Choice

Which of the following best describes the concept illustrated by the lever in the diagram?

• A) Machines can create energy.

• B) Machines can eliminate the need for force.

• C) Machines trade force for distance.

• D) Machines increase the total work done.

Multiple Choice

What is the main advantage of using a simple machine according to the image?

• It reduces the amount of work.

• It allows a smaller force over a greater distance.

• It increases the amount of work.

• It decreases the distance moved.

Multiple Choice

Fill in the blank: In a simple machine, the formula for work is W = F x ____.

• A) D

• B) M

• C) T

• D) V

Multiple Choice

According to the image, what happens when you apply a greater distance in a simple machine?

• Less force is needed.

• More force is needed.

• The work done is reduced.

• The work done is increased.

Multiple Choice

What is the formula for calculating the mechanical advantage (MA) of a lever?

• MA = Load Arm Length / Effort Arm Length

• MA = Effort Arm Length / Load Arm Length

• MA = Load Arm Length x Effort Arm Length

• MA = Effort Arm Length - Load Arm Length

Multiple Choice

Fill in the blank: If the effort arm length is 40 cm and the load arm length is 10 cm, the mechanical advantage (MA) is ____.

• A) 2

• B) 3

• C) 4

• D) 5

Multiple Choice

In the given diagram, if the effort force is 10 newtons and the resistance force is 30 newtons, what is the mechanical advantage (MA) of the lever?

• 1

• 2

• 3

• 4