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Total questions: 66
Worksheet time: 3hrs 1mins
What is the main purpose of machines according to the text?
To increase friction
To reduce the weight of objects
To help us do work more quickly, easily, and safely
To create energy
Which of the following is NOT a type of simple machine mentioned in the text?
Complex Machine
Inclined Plane
Lever
Wedge
What is a lever defined as in the text?
A device that uses energy to help you do work
A machine that can lift heavy things
A type of complex machine
A tool with no moving parts
Which simple machine is described as a surface with a slope?
Pulley
Inclined Plane
Screw
Wedge
Which of the following is an example of a complex machine?
Wedge
Inclined Plane
Bicycle
Hammer
A seesaw is an example of what type of simple machine?
wheel and axle
lever
wedge
pulley
What type of simple machine makes chopping wood easier?
inclined plane
screw
wedge
lever
The ____________ consists of a rod attached to a wheel, and makes it easier to move or turn things. A door knob is an example of this simple machine.
lever
pulley
wheel and axle
wedge
A ________________ is a combination of two or more
simple machines. Examples include scissors, wheelbarrow,
and a bicycle.
compound machine
quarter machine
simple machine
complex machine
Which of the following is not the advantage of machines?
Help to increase air pollution
Help to travel
Help to know the time
Help to move heavy objects
Which of the following simple machines can be used to cut objects ?
Wedge
gear
Pulley
Inclined plane
Diagram shows the positions of the load, fulcrum and force in a lever.
Which of the following activities uses the same class of lever shown?
Which of the following simple machines comprises a V-shaped metal piece with a sharp edge?
Wheel and axle
Gear
Wedge
Lever
The transfer of energy to a body by the application of a force that causes the body to move in the direction of the force.
Power
Work
Force
Speed
A quantity that measures the rate at which work is done or energy is transformed.
Work
Kinetic Energy
Power
Potential Energy
A quantity that measures how much a machine multiplies force or distance.
Energy
Power
Work
Mechanical Advantage
This 2000 N weight is raised 1 meter by pulling 4 meters of rope. What force was required to pull the rope?
To lift this 2000 N weight to a height of 1 meter by hand, a mover did 2000 joules of work. Assuming the pulleys are frictionless, how much work does he do when using this block-and-tackle device?
What is effort (input) force?
the force one exerts on a machine
the force which an effort force must overcome in order to do work on an object via a simple machine.
the force the machine exerts on a object
the output work times the input distance
the percentage of the input work that is converted to output work
mechanical advantage
efficiency
joule
machine
An effort of 640 newtons is applied to this pulley system. What is the load that it will lift?
1280
1600
1920
2560
A box of weight W is lifted by a force F using a lever as shown below.
What is the mechanical advantage of the lever (MA=Input Distance/Output Distance)?
0.5
2
3
6
Using a lever, Joe is able to lift a 10,000 N car off of the ground with a force of 1000 N. What is the mechanical advantage of the lever (MA=Output Force/Input Force)?
1
10
100
1000
A pulley has a mechanical advantage equal to 1 because.....
The output force is larger than the input force.
The output force is smaller than the input force.
The output and input force are equal, but the direction of the force changes.
None of the above.
A machine's _______________ is determined by comparing the input and output forces.
efficiency
mechanical advantage
work
friction
The _________ of a machine is always less than 100%.
mechanical advantage
friction
force
efficiency
How does using a jack to lift a car make work easier?
it changes the size of the foce
it changes the distance the force acts
it changes the direction a force acts
none of the above
Why can mechanical efficiency never be 100%?
No machine is strong enough.
Machines are too big to allow for 100% efficiency.
It can be 100%.
Some energy is lost in the form of heat/sound due to friction.
What happens to the overall efficiency of a machine as I add more machines?
For each simple machine you add, the overall efficiency increases because it gets faster.
For each simple machine you add, the overall efficiency decreases.
The overall efficiency is divided in half for every simple machine you add.
There is no connection.
the amount of work you do when you exert one Newton of force to move the object one meter
joule
newton
meter
output force
the rate at which work is done
power
work
machine
efficiency
a machine that utilizes two or more simple machines
compound machine
machine
wedge
screw
a simple machine made of a grooved wheel with a rope or cable wrapped around it
pulley
wheel and axle
screw
lever
a simple machine made of two circular or cylindrical objects fastened together that rotate about a common axis
wheel and axle
pulley
screw
compound machine
A machine with a ratio less than 1:
multiplies the input force so the machine would be good to help move heavy objects.
does not multiply the force, but increases distance and speed.
is good for lifting and moving objects quicker.
Is not good for lifting or moving objects quicker.
Real machines:
actually exist
have an efficiency less than 100%
lose energy due to friction
all are correct
which lever type is a wheel barrow?
type 1
type 2
type 3
none of them
the mechanical advantage of a wheel and axle is...
wheel diameter / force
wheel diameter / axle diameter
axle diameter / wheel diameter
What is resistance (output) force?
the force required by a machine in order to accomplish work (the force you put on the machine)
The force that is exerted by a machine
the force the machine exerts on a object
the output work times the input distance
What is effort (input) force?
the force one exerts on a machine
the force which an effort force must overcome in order to do work on an object via a simple machine.
the force the machine exerts on a object
the output work times the input distance
What is the mechanical advantage of a pulley system that looks like this?
5
8
1
2
