WorksheetsScience 8 Unit D 2.0
Total questions: 48
Worksheet time: 3605secs
Name
Class
Date
1.
How much work is produced when 350 N is used to move a car 5 m?
a)
70 J
b)
1750 J
c)
355 J
d)
175 J
2.
What is the mechanical advantage of the pulley system in the picture?
a)
2
b)
3
c)
4
d)
5
3.
How does a single fixed pulley, like the one seen here, help you do work?
a)
changes the direction of the force
b)
increases the amount of applied force
c)
decreases the amount of applied force
d)
allows you to pull the rope a shorter distance
4.
In which of these cases is work being done?
a)
A student sleeps
b)
A student pushes a locked door that does not move
c)
a student carries his chair into another room
d)
A student sits on the carpet
5.
The mechanical advantage of this inclined plane is.....
a)
2.4
b)
3.4
c)
4.4
6.
How can you decrease the effort force needed to push a weight to the top of the ramp?
a)
cover the surface with carpet
b)
increase the length of the ramp
c)
increase the height of the ramp
d)
decrease the length of the ramp
7.
A 16 N force is applied to an object and 96 J of work is done. How far was the object moved?
a)
6 m
b)
16 m
c)
80 m
d)
1536 m
8.
What is the efficiency of a machine if 55.3 J of work are done on the machine, but only 14.3 J is produced by the machine?
a)
0.25 J
b)
26%
c)
386%
d)
3.86 J
9.
What is the efficiency of the machine if the work input is 263 J and the work output is 142 J?
a)
6.26%
b)
54%
c)
100%
d)
260%
10.
if a load of a lever is 100 newtons and the force you apply is 20 newtons, what is your mechanical advantage?
a)
120 N
b)
5 N
c)
2000 N
d)
80 N
11.
What is the equation for mechanical advantage?
a)
MA=input force*output force
b)
MA=output force/input force
c)
MA=input force/output force
d)
MA= output force - input force
12.
What is the mechanical advantage if you lift a load of 300 newtons and you only push down with 50 newtons?
a)
250
b)
50
c)
60
d)
6
13.
True or False: No machine is 100 % efficient.
a)
True
b)
False
14.
A machine's ability to convert input work to output work
a)
efficiency
b)
power
c)
input force
d)
mechanical advantage
15.
What is the speed ratio if you push down a lever 10 m from the fulcrum and the load is lifted 2 m?
a)
5
b)
10
c)
2
d)
1
16.
Machines don't reduce energy you need to move things, but they reduce what?
a)
Weight
b)
Mass
c)
Force
d)
Height
17.
The SI unit of work is the
a)
Newton
b)
Joule
c)
Watt
18.
The force that is exerted on a machine is called the _______ force
a)
input
b)
output
19.
True or False?
You do work only when you exert a force on an object and move it
You do work only when you exert a force on an object and move it
a)
true
b)
false
20.
Both work and energy are measured in
a)
joules
b)
newtons
c)
meters
d)
seconds
21.
If you push a cart with a force of 60 N for 2 m, how much work have you done?
a)
120 J
b)
30 J
c)
120 N
d)
30 N
22.
If 68 Joules were necessary to move a 4 Newton crate, how far was the crate moved?
a)
272 m
b)
17 m
c)
4.05 m
d)
272 cm
23.
A boy pushes on a parked car with a force of 200 N. The car does not move. How much work does the boy do on the car?
a)
200N
b)
200J
c)
0J
d)
0N
24.
A person applies a force to a wall.
a)
Work is done because the person uses energy when applying the force
b)
Work is done because the wall heats up at the place where the force is applied
c)
No work is done
25.
The amount of force pushing on an area is the definition of....
a)
Fluid
b)
Viscosity
c)
Barometer
d)
Pressure
26.
The rule that when force is applied to a confined fluid, the increase in pressure is transmitted equally throughout.
a)
pascal's principle
b)
bernoulli's principle
c)
archimedes' principle
d)
Newton's Law
27.
If you buy a machine that has an efficiency of 82%, what happened to the other 18%?
a)
The energy was lost to friction, heat and other forms of energy
b)
There is not enough information given
28.
What is the efficiency of the machine if the input is 263 J and the output is 142 J?
a)
6.26%
b)
54%
c)
100%
d)
260%
29.
How can a machine make work easier for you?
a)
by decreasing the amount of work you do
b)
by decreasing your effort force
c)
by increasing the work done by the machine
d)
none of the above
30.
If a sailor pulls 3.9m on a pulley rope and the sail goes up 1.8m, what is the speed ratio of the pulley system?
a)
1.8
b)
2.2
c)
7.02
d)
14.2
31.
Which wastes more energy?
a)
A more efficient machine
b)
A less efficient machine
32.
In what way do most machines or processes transfer wasted energy to their surroundings?
a)
by movement
b)
by light
c)
by electricity
d)
by heat
33.
If a wheel and axle is turned 1.6m a baby dragon is lifted 0.3m, what is the speed ratio of the pulley system?
a)
0.3
b)
0.48
c)
1.6
d)
5.3
34.
If you push a lever 0.8m with a force of 12N, and a 30N baby alligator is lifted 0.2m, what is the efficiency of the lever system?
a)
12%
b)
16%
c)
30%
d)
63%
35.
If you push a stubborn baby elephant up a 3.2m inclined plane using a force of 24N, and the 52 N baby alligator is lifted 1.1m, what is the efficiency of the inclined plane?
a)
18%
b)
46%
c)
74%
d)
96%
36.
What is the efficiency of a machine with a Mechanical Advantage of 3.3 and a Speed Ratio of 4.7?
a)
33%
b)
47%
c)
70%
d)
95%
37.
What is the efficiency of a typical car engine?
a)
5%
b)
15%
c)
30%
d)
45%
38.
What is the picture showing?
a)
pneumatic jack
b)
hydraulic jack
c)
compression system
d)
decompression chamber
39.
To have a mechanical advantage, the load would be placed on which piston?
a)
Piston A
b)
Piston B
40.
To reduce the effect of heat on a mechanical system, ______________ would be used.
a)
fans and lubricants
b)
fans and gears
c)
lubricants and gears
d)
belts and chains
41.
A girl pushes on a parked car with a force of 500N. The car does not move. How much work does the girl do?
a)
500 N
b)
500 J
c)
Zero
d)
Can't be determined-need a distance
42.
A man pushes a crate along a factory floor by exerting a force of 50 N. If the crate moves a distance of 4.0 m, how much work does the man perform?
a)
13.75 J
b)
200 N
c)
200 J
d)
13.75 N
43.
A man pushes a crate along a factory floor by exerting a force of 50 N. If the crate moves a distance of 4.0 m, how much work does the man perform?
a)
13.75 J
b)
200 N
c)
200 J
d)
13.75 N
44.
What pressure does a 4000N horse exert on the ground if each foot is 10cm2?
a)
40 N/cm2
b)
100 N/cm2
c)
400 N/cm2
d)
10 N/cm2
45.
What is the pressure in the hydraulic fluid?
a)
1210 N
b)
484 N/m2
c)
8000 N
d)
3025 N/m2
46.
What is the force up on the mailbox?
a)
1210 N
b)
8000 N
c)
7744 N
d)
5655 N
47.
What principle is this hydraulic press showing?
a)
Archimedes' Principle
b)
Bernoulli's Principle
c)
Pascal's Principle
d)
Principle Testa
48.
Which is the force made on the piston?
a)
400 N
b)
100 N
c)
40 N
d)
1000 N
100 %
