Energy y9 Flashcards
1
Q
What is the standard unit of energy in the International System of Units (SI)?
A
Joule (J)
2
Q
Convert 1 kilojoule (kJ) to joules (J).
A
1000 joules
3
Q
What is the formula for calculating work done?
A
Work = Force × Distance
4
Q
True or False: Work is done when a force causes an object to move.
A
True
5
Q
Fill in the blank: Kinetic energy is given by the equation KE = 1/2 _ _ _.
A
mv squared
6
Q
What is the unit of work in the SI system?
A
Joule (J)
7
Q
What is the change in energy of a system when work is done on it?
A
The energy increases.
8
Q
True or False: Energy can be created or destroyed.
A
False
9
Q
What is the unit of power?
A
Watt (W)
10
Q
How is power related to work?
A
Power = Work / Time
11
Q
What type of energy is associated with the motion of an object?
A
Kinetic energy
12
Q
What is elastic potential energy?
A
Energy stored in elastic materials as the result of their stretching or compressing.
13
Q
What is the equation for gravitational potential energy?
A
PE = mgh
14
Q
What does the variable ‘m’ represent in the gravitational potential energy equation?
A
Mass of the object
15
Q
What does the variable ‘g’ represent in the gravitational potential energy equation?
A
Acceleration due to gravity
16
Q
Fill in the blank: The total mechanical energy of a system is the sum of its ___ and ___ energy.
A
kinetic; potential
17
Q
What is the energy conversion efficiency?
A
The ratio of useful output energy to the input energy.
18
Q
True or False: A joule is equal to one watt-second.
A
True
19
Q
What type of energy transformation occurs in a battery-powered device?
A
Chemical energy to electrical energy
20
Q
What is the kinetic energy of an object with a mass of 2 kg moving at a speed of 3 m/s?
A
9 Joules
21
Q
Fill in the blank: The energy stored in food is primarily in the form of ___ energy.
A
Chemical
22
Q
What is the formula for calculating the work done when a constant force is applied?
A
Work = Force × Distance
23
Q
True or False: Energy can be transferred from one form to another.
A
True
24
Q
What is the unit of measurement for energy efficiency?
A
Percentage (%)
25
What does a watt measure?
Power
26
Convert 1 horsepower to watts.
746 watts
27
What is the work-energy principle?
The work done on an object is equal to the change in its kinetic energy.
28
What is the equation for calculating the work done by a variable force?
Work = ∫ F(x) dx
29
Fill in the blank: The energy associated with the position of an object in a gravitational field is called ___ energy.
gravitational potential
30
What is the main form of energy in a hydroelectric power plant?
Mechanical energy from moving water
31
What is thermal energy?
The total kinetic energy of particles in a substance.
32
True or False: The energy in a system can change forms but the total energy remains constant.
True
33
What is the primary form of energy used in nuclear power plants?
Nuclear energy
34
What is the formula for calculating kinetic energy?
KE = 1/2 mv²
35
What does the variable 'v' represent in the kinetic energy equation?
Velocity of the object
36
What type of energy is associated with the arrangement of atoms in a molecule?
Chemical energy
37
Convert 1 joule to newton-meters.
1 newton-meter
38
What is the unit of measure for work done over time?
Power (Watt)
39
What is the principle of conservation of mechanical energy?
In the absence of non-conservative forces, the total mechanical energy remains constant.
40
Fill in the blank: The energy stored in a compressed spring is an example of ___ energy.
elastic potential
41
What is the relationship between work and energy?
Work is a transfer of energy.
42
True or False: An object at rest has kinetic energy.
False
43
What is the energy transformation that occurs when a light bulb is turned on?
Electrical energy to light and thermal energy
44
What is the role of friction in energy transfer?
Friction converts mechanical energy into thermal energy.
45
What is the formula for gravitational potential energy?
PE = mgh
46
Convert 1 joule to foot-pounds.
0.73756 foot-pounds
47
What is the term for the energy stored in the bonds of chemical compounds?
Chemical energy
48
Fill in the blank: The sum of kinetic and potential energy in a system is called ___ energy.
mechanical
49
What is the primary form of energy in the human body?
Chemical energy from food
50
What is the unit of measure for energy in thermodynamics?
Joule (J)
51
True or False: Energy can exist in multiple forms simultaneously.
True
52
What is the work done against gravity when lifting an object?
Equal to the change in gravitational potential energy.
53
What is the energy transformation that occurs during combustion?
Chemical energy to thermal energy
54
What type of energy is released during a nuclear reaction?
Nuclear energy
55
What is the significance of the energy conservation principle in physics?
It helps to understand that energy can change forms but the total amount remains constant.
56
Fill in the blank: The energy of a moving object is called ___ energy.
kinetic
57
What is the definition of work in physics?
Work is done when a force acts on an object to move it in the direction of the force.
58
What is the formula for kinetic energy?
Kinetic energy (KE) is given by the formula KE = 1/2 mv², where m is mass and v is velocity.
59
True or False: Potential energy depends on the height of an object above a reference point.
True
60
Fill in the blank: The formula for gravitational potential energy is ______.
PE = mgh, where m is mass, g is acceleration due to gravity, and h is height.
61
What does the symbol 'm' represent in energy equations?
'm' represents mass.
62
What is the unit of energy in the International System of Units (SI)?
The unit of energy is the joule (J).
63
Multiple choice: Which of the following is a form of energy? A) Thermal B) Kinetic C) Potential D) All of the above
D) All of the above
64
What is the work-energy principle?
The work-energy principle states that the work done on an object is equal to the change in its kinetic energy.
65
True or False: Energy can be created or destroyed.
False
66
Fill in the blank: The formula for elastic potential energy is ______.
PE = 1/2 kx², where k is the spring constant and x is the displacement.
67
What is the relationship between work and energy?
Work is the transfer of energy.
68
Multiple choice: Which equation represents the conservation of mechanical energy? A) KE + PE = constant B) KE = PE C) W = Fd D) None of the above
A) KE + PE = constant
69
What is the formula for the total mechanical energy of a system?
Total mechanical energy (E) is E = KE + PE.
70
True or False: The total energy of a closed system remains constant.
True
71
What is the formula for work done by a constant force?
Work (W) is given by W = Fd cos(θ), where F is the force, d is the distance, and θ is the angle between the force and the direction of motion.
72
Fill in the blank: The formula for power is ______.
Power (P) = Work (W) / Time (t).
73
What is mechanical energy?
Mechanical energy is the sum of kinetic and potential energy in a system.
74
Multiple choice: Which type of energy is associated with motion? A) Potential B) Kinetic C) Thermal D) Chemical
B) Kinetic
75
What is the principle of conservation of energy?
The principle states that energy cannot be created or destroyed, only transformed from one form to another.
76
True or False: An object at rest has kinetic energy.
False
77
Fill in the blank: The formula for the gravitational force near the Earth's surface is ______.
F = mg, where F is the force, m is mass, and g is acceleration due to gravity.
78
What is the relationship between potential energy and height?
Potential energy increases with height.
79
Multiple choice: What type of potential energy is stored in a compressed spring? A) Gravitational B) Elastic C) Chemical D) None of the above
B) Elastic
80
What is the formula for calculating gravitational potential energy?
Gravitational potential energy (PE) is calculated using PE = mgh.
81
True or False: Energy can be transferred between systems.
True
82
What does 'g' represent in potential energy equations?
'g' represents the acceleration due to gravity, approximately 9.81 m/s² on Earth.
83
What is the unit of energy?
Joule (J)
84
True or False: Kinetic energy depends on mass and velocity.
True
85
Fill in the blank: The formula for gravitational potential energy is ______.
mgh
86
What type of energy is stored in a compressed spring?
Elastic potential energy
87
Multiple Choice: What is the kinetic energy of an object with a mass of 2 kg moving at a velocity of 3 m/s? A) 3 J B) 6 J C) 9 J D) 12 J
3 J
88
What is the principle of conservation of energy?
Energy cannot be created or destroyed, only transformed.
89
True or False: Work is done when a force causes displacement.
True
90
Fill in the blank: The energy of motion is called ______.
Kinetic energy
91
What is the formula for calculating work done?
Work = Force × Distance × cos(θ)
92
Multiple Choice: Which of the following is NOT a form of energy? A) Thermal B) Chemical C) Color D) Nuclear
Color
93
What happens to the energy of an object when it falls?
It converts potential energy to kinetic energy.
94
True or False: Power is the rate at which work is done.
True
95
Fill in the blank: The SI unit of power is ______.
Watt (W)
96
What is the formula for calculating power?
Power = Work / Time
97
Multiple Choice: If a machine does 100 J of work in 5 seconds, what is its power output? A) 10 W B) 20 W C) 50 W D) 100 W
20 W
98
What type of energy is associated with the position of an object?
Potential energy
99
True or False: Mechanical energy is the sum of kinetic and potential energy.
True
100
Fill in the blank: The energy stored in food is a form of ______ energy.
Chemical
101
What is the relationship between mass and energy according to Einstein's theory?
E = mc²
102
Multiple Choice: Which of the following is an example of kinetic energy? A) A rock on a hill B) A moving car C) A stretched rubber band D) A battery
A moving car
103
What is the effect of friction on energy?
Friction converts mechanical energy into thermal energy.
104
True or False: Energy efficiency is the ratio of useful energy output to total energy input.
True
105
Fill in the blank: The total energy in a closed system remains ______.
Constant
106
What is the potential energy of a 10 kg object at a height of 5 m? (Use g = 9.8 m/s²)
490 J
107
Multiple Choice: Which energy transformation occurs in a battery-powered device? A) Chemical to Electrical B) Electrical to Mechanical C) Thermal to Kinetic D) All of the above
All of the above
