Phys101 Flashcards
(83 cards)
1
Q
What is Net Force?
A
The vector sum of all force vectors that acts on an object.
2
Q
What are Free-Body Diagrams used for?
A
Diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation.
3
Q
What is the relationship between weight and mass?
A
Weight is the gravitational force acting on an object, while mass is the amount of matter in the object.
4
Q
What is the SI unit of weight?
A
Newton (N)
5
Q
Define mass.
A
The amount of matter in the object; mass is scalar.
6
Q
What are the Fundamental Forces?
A
- Gravitational
- Electromagnetic
- Strong nuclear Force
- Weak nuclear Force
7
Q
What is Tension Force?
A
Transmitted force through rope, cable, or wire when it is pulled.
8
Q
What is Normal Force?
A
Exerted force upon an object in contact with another stable object.
9
Q
What does Newton’s First Law state?
A
If the net force on an object is equal to zero, the object will remain at rest or in motion with the same constant velocity.
10
Q
What is Inertia?
A
An object’s resistance to change its motion.
11
Q
What does Newton’s Second Law describe?
A
The relationship between net external force, mass, and acceleration.
12
Q
What is the direction of acceleration according to Newton’s Second Law?
A
Acceleration has the same direction as the net force causing it.
13
Q
What does Newton’s Third Law state?
A
The forces that two interacting objects exert on each other are always equal in magnitude and opposite in direction.
14
Q
What is the direction of the Normal Force?
A
Always perpendicular to the plane of the contact surface.
15
Q
What is the formula for work done by a constant force?
A
Work = force × displacement × cos(α)
16
Q
What is the SI unit of work?
A
Joule (J)
17
Q
What is positive work?
A
Transfer of energy to the object.
18
Q
What is negative work?
A
Transfer of energy from the object.
19
Q
What is the formula for gravitational force?
A
Weight (w) = mass (m) × gravitational acceleration (g)
20
Q
What is the gravitational acceleration on Earth?
A
Approximately 9.8 m/s²
21
Q
What is the relationship between force, mass, and acceleration?
A
Force = mass × acceleration (F = ma)
22
Q
What happens to an object’s velocity if no net force acts on it?
A
The object’s velocity remains constant.
23
Q
Fill in the blank: A projectile reaches its maximum height when the launch angle is ______.
A
45 degrees
24
Q
What is the shape of a projectile’s trajectory?
A
Parabolic
25
What are the two components of projectile motion?
* Horizontal component
* Vertical component
26
What is the effect of air resistance on ideal projectile motion?
Ideal projectile motion neglects air resistance.
27
What is the acceleration of an object in free fall?
Constant downward acceleration due to gravity.
28
What happens to the velocity of an object thrown upward at its maximum height?
The velocity is zero.
29
What is the formula to calculate kinetic energy?
Kinetic Energy = 1/2 × mass × velocity²
30
What is the relationship between work and energy?
Work is the energy transferred to or from an object due to the action of a force.
31
What is the Kinetic energy of a 30 kg object moving at 4 m/s?
Kinetic energy = 240 J
## Footnote
Kinetic energy (KE) is calculated using the formula KE = 0.5 * m * v^2, where m is mass and v is velocity.
32
What is the velocity of a 2 kg object with a kinetic energy of 100 J?
Velocity = 10 m/s
## Footnote
The velocity can be found using the formula KE = 0.5 * m * v^2 and solving for v.
33
What are other units for energy?
* electron-volt: 1 eV = 1.602 × 10^-19 J
* calorie: 1 cal = 4186 J
* mega-ton: 1 Mt = 4.18 × 10^15 J
## Footnote
These units are used in various scientific contexts.
34
What is Kinetic Energy?
Energy associated with motion
## Footnote
Kinetic energy is a scalar quantity, measured in Joules (J).
35
What is the unit of Kinetic Energy?
Joule (J)
## Footnote
1 J = 1 Nm = 1 kg·m²·s⁻².
36
Is Kinetic Energy always positive or zero?
Yes, Kinetic energy is always positive or zero (K=0 for an object at rest)
## Footnote
This emphasizes that kinetic energy cannot be negative.
37
What does the symbol K represent?
Kinetic energy
## Footnote
K is commonly used to denote kinetic energy in equations.
38
What does the symbol m represent?
Mass
## Footnote
m is the mass of the object in kilograms.
39
What does the symbol v represent?
Velocity
## Footnote
v is the velocity of the object in meters per second.
40
What are the forms of energy in our daily lives?
* Mechanical energy
* Thermal energy
* Chemical energy
* Electromagnetic energy
* Solar energy
* Electrical energy
* Nuclear energy
## Footnote
These forms represent the various ways energy is utilized and transformed.
41
What is the definition of energy?
The ability to do work
## Footnote
Energy is a fundamental concept in physics with various forms and applications.
42
What is the work done by a constant force in one dimension when the force and displacement are in the same direction?
W = Fd (positive work)
## Footnote
Here, W is work, F is force, and d is displacement.
43
What is the work done by a constant force in one dimension when the force and displacement are in opposite directions?
W = -Fd (negative work)
## Footnote
Negative work indicates that the force is acting against the direction of displacement.
44
What is the work done by the gravitational force on an object tossed vertically upward?
The work is negative
## Footnote
This is because the displacement and gravitational force point in opposite directions.
45
What is the work done by the gravitational force on an object falling down?
The work is positive
## Footnote
This indicates that the gravitational force and displacement are in the same direction.
46
What is the Work-Kinetic Energy Theorem?
The relationship between kinetic energy of an object and the work done by the forces acting on it.
## Footnote
This theorem states that the work done on an object is equal to the change in its kinetic energy.
47
What is the acceleration due to gravitational force?
g = 9.8 m/s²
## Footnote
This value is constant near the surface of the Earth.
48
What is the definition of potential energy?
The energy stored in the configuration of a system of objects that exert forces on each other.
## Footnote
Potential energy is also a scalar quantity measured in Joules (J).
49
What is the unit of Potential Energy?
Joule (J)
## Footnote
The unit of potential energy is the same as that of kinetic energy.
50
What is the difference between static and kinetic friction?
* Static friction: friction when an object is at rest
* Kinetic friction: friction when the object is moving
## Footnote
Static friction is usually greater than kinetic friction.
51
What characterizes static friction?
The friction force is equal in magnitude and opposite in direction to the external force until the threshold is reached.
## Footnote
Once the threshold is exceeded, the object begins to move.
52
What characterizes kinetic friction?
The kinetic friction force is always opposite to the direction of the motion of the object.
## Footnote
This force acts to slow down the moving object.
53
What is the formula for calculating power?
P = W/t
## Footnote
Where P is power, W is work done, and t is time taken.
54
What is the SI unit of power?
Watt (W)
## Footnote
1 Watt is equivalent to 1 Joule per second.
55
What are derived quantities in the SI unit system?
* Area: m²
* Volume: m³
* Density: kg/m³
* Velocity: m/s
* Acceleration: m/s²
## Footnote
Derived quantities are formed by combining base quantities.
56
What is the definition of a physical quantity?
Quantity that can be measured.
## Footnote
Physical quantities are categorized into basic and derived quantities.
57
What are the base units in the SI unit system?
* Meter (m) - length
* Kilogram (kg) - mass
* Second (s) - time
* Ampere (A) - current
* Kelvin (K) - temperature
* Mole (mol) - amount of a substance
* Candela (cd) - luminous intensity
## Footnote
These units are fundamental to measurements in physics.
58
What is potential energy?
The energy stored in the configuration of a system of objects that exert forces on each other
## Footnote
Potential energy is scalar and measured in Joules (J)
59
What is the unit of potential energy?
Joule (J)
## Footnote
1 J = 1 Nm = 1 kg.m².s⁻²
60
What is gravitational potential energy (U)?
Potential energy associated with the height of an object in a gravitational field
61
How is the change in potential energy calculated?
The work for lifting an object is given by the formula: ΔU = mgh
## Footnote
Where m is the mass, g is the gravitational acceleration, and h is the height of the object
62
Define momentum.
The product of an object's mass and its velocity
## Footnote
Momentum is a vector quantity
63
What is the SI unit of momentum?
kg m/s
## Footnote
Also expressed as kg.m.s⁻¹
64
What does impulse represent?
The time integral of force or the change in momentum
## Footnote
Impulse is also a vector quantity
65
What are the types of collision?
* Elastic collision
* Inelastic collision
* Totally inelastic collision
66
State the conservation of linear momentum principle.
The sum of the momentum after collision is the same as the sum of momentum before collision
67
What is the definition of work done by a conservative force?
The change in potential energy is equal to the negative of the work done by the conservative force
68
What is a conservative force?
Any force for which the work done over any closed path is zero
69
Give an example of a nonconservative force.
Friction force
## Footnote
The work done by friction is not zero over a closed path
70
What is the formula for kinetic energy?
Kinetic energy (KE) = 1/2 mv²
71
What is speed?
The absolute value (magnitude) of velocity
## Footnote
Speed is scalar and always positive
72
What is the difference between displacement and distance?
* Displacement is a vector quantity
* Distance is a scalar quantity
73
How is average acceleration defined?
The velocity change per time interval
74
What does the slope of a position-time graph represent?
The velocity of the object at the corresponding position
75
What is the relationship between velocity and acceleration?
If velocity and acceleration are in the same direction, the object moves faster; if they are in opposite directions, the object slows down
76
What defines an isolated system?
A system of objects that exert force on one another without external forces causing energy changes within the system
77
What is Hooke's Law?
The force exerted by a spring is proportional to its displacement from the equilibrium position
78
Fill in the blank: The unit of acceleration is _______.
m/s²
79
What is the formula for calculating the net force from potential energy?
F = -dU/dx
## Footnote
Where U is potential energy and x is position
80
What does the area under a velocity-time graph represent?
The displacement of the object
81
What is the significance of unit vectors?
They have a magnitude of 1 and indicate direction along the main coordinate axes
82
What is the formula for calculating work done by a variable force?
W = ∫ F(x) dx
83
What is the significance of the maximum point in a block-spring system?
It represents the amplitude (maximum elongation of the spring from the equilibrium position)
