WorksheetsMachines
Total questions: 30
Worksheet time: 29mins
An object being lifted or moved is a
load
fulcrum
effort
work
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 efficiency of a machine if 56 J of work are done on the machine, but only 14 J is produced by the 1machine?
0.25 J
25%
400%
4 J
What is the VR of this pulley system?
2
3
4
5
A load of 650 newtons is lifted with this pulley. What is the effort required to do this work?
300
325
600
650
What is the mechanical advantage of this pulley system?
4
5
6
7
What is this part of pulley?
Axle
Groove
Rope
Wheel
Which one is an example of a pulley system?
an ax
a ramp
an elevator
a see-saw
What term is used to mean the object that is being moved by a machine?
pulley
effort
fulcrum
load
Let's say you wanted to use a pulley to lift a flag up a flagpole. If you wanted to lift the flag 10 meters in the air, how far would you have to move the rope?
5 meters
10 meters
15 meters
20 meters
How do fixed pulleys make work easier?
they change the direction of a force
they change the amount of force required
the distance over which the force is applied
the measurement of an object
Identify the type of pulley
Fixed
Movable
Block and Tackle or pulley system
The more supporting strings a pulley system has, the less efficient it is because ___________________.
there is more friction
its harder to lift the load
there is more weight
you are changing the direction of the force
The car that your family owns is about 15% efficient. This means that if you put in 100 L of gasoline, about 85 L will be wasted
True
False
Calculate the efficiency of the following device:
Input force = 50 N
Output force = 450 N
Input distance = 1.8 m
Output distance = 18cm
10%
9%
90%
20%
In a gear system you have built in a laboratory, the input distance is 25 cm and the output distance is 4 cm. What is the velocity ratio?
6.25
0.16
20
100
In a block and tackle system, the effort force moves _____ as the load moves _____.
downward, up
sideways, down
upward, sideways
sideways, up
Which type of pulley only changes the direction of the force?
A compound pulley
A block and tackle system
A movable pulley
A single fixed pulley
What is the ideal mechanical advantage of this pulley? (Hint: Load is equal to the number of tensions supporting it)
3
4
5
6
In a practical machine (that has η < 100%), the relationship between MA and VR is given as
MA = VR
MA < VR
MA > VR
MA and VR are 0
Select the chief cause of energy loss in a practical machine (select all that apply)
friction
weight of moving parts
non-rigid and inelastic parts
sound
power cut
