acceleration

1.  The rate of change of velocity

STANDARD METER

1.  The distance between two engraved marks at the ends of a rod made of platinum and Iridium alloy kept at 0°C.

DERIVED  physical quantity

1.  A physical quantity that can be defined in terms of the fundamental physical quantities.

the fundamental physical quantities.

1.  A physical quantity that cannot be defined in terms of other physical quantities

STANDARD KILOGRAM

1.  The mass of a cylinder made of platinum and Iridium alloy of specific dimensions at the International Bureau of Weights

      and Measures

MEASURAMENT PROCWSS

1.  Comparing a physical quantity with another quantity of its kind to find out how many times the first includes the second.

THE SECOND

1.  A part of 86400 of the average solar day

DISPLACEMENT

1.  The straight line segment in a certain direction between a starting point and end point

VECTOR QUANTITY

1.  A physical quantity that can be fully defined by its magnitude and direction

SCALAR QUANTUTY

1.  A physical quantity that can be fully defined by its magnitude only

THE RESULTANT FORCE

1.  A single force produces the same effect on an object as that produced by a number of forces acting on it.

TRANSLATION MOTION

1.  A type of motion which is characterized by having a starting point and end point

PERIODIC MOTION

1.  The motion that repeats itself over equal intervals of time

AVERAGE VELOCITY

1.  The quotient of total displacement and total time.

UNIFORM VELOCITY

1.  The object velocity when it is displaced through equal displacements in equal times.

INSTANTANEOUS VELOCITY

1.  The velocity of the object at a given instant.

MOTION

1.  The change in the object position as the time passes

VELOCITY

1.  The displacement of the object in one second.

THE ACCELERATION

1.  The change of the object velocity per unit time.

THE ACCELERATION DUE TO GRAVITY

1.  The uniform acceleration by which objects move during free fall.

DISPLACEMENT

1.  Numerically equal to the area below the curve in velocity-time graph.

UNIFORM ACCELERATION

1.  A type of acceleration when the rate of change of velocity is constant.

FREE FALL

1.  The fall of objects under the effect of their weight only.

Newton’s FIRST law OF MOTION

1.  Newton’s law that states that: A static object keeps its state of rest, and a moving object keeps its state of motion at

       uniform velocity in a straight line unless acted upon by a resultant force.

THE FORCE

1.  An external influence that affects the object to change its state or direction of motion.

Newton’s THIRD law OF MOTION

1.  Newton’s law that states that: For every action there is a reaction equal in magnitude and opposite in direction

SPRING SCALE

1.  The tool used to measure force.

INERTIA

1.  Resistance of object to change its kinematics state.

INERTIA

1.  Tendency of an object to keep either its state of rest or state of motion at its original velocity uniformly in a straight line.

WEIGHT

1.  The force of gravity acting on the body.

CIRCULAR MOTION

1.  The motion of a body in a circular path at a constant speed but of changeable direction.

PERIODIC TIME

1.  The time taken by the body to cover the circumference of a circle.

THE CENTRPETAL FORCE

1.  The force that continuously acts normally to the motion of a body, changing its straight path into circular.

THE CENTRPETAL ACCELARATION

1.  The acceleration acquired by a body in circular motion due to a change in the direction of velocity.

Gravitational Field

1.  The area where the forces of gravitation take place.

The intensity of Earth's gravitational field

1.  The gravitational force of the Earth on a body of mass 1kg

Newton's general gravitational law

1.  The law that states: A materialistic body attracts another by a force that is directly proportional to the product of

Their masses and inversely proportional to square the distance between them.

The Joule

1.  The work done by a force of one Newton to move an object through a displacement of one meter in the direction of the force

KINETIC ENERGY

1.  The energy possessed by an object due to its motion

MECHANICAL ENERGY

1.  The energy that equals the sum of the kinetic energy and the potential energy of an object

POTENTIAL ENERGY

1.  The energy stored in an object due to its position

ENERGY

1.  The capacity to do work.

THE CONSERVATION LAW OF ENERGY

1.  Name of the law that states: Energy is neither created nor destroyed but it is converted from one form into another

The heat capacity of a body

1.  the quantity of heat energy needed to raise the temperature of the body by one Kelvin.

MECHANICAL ENERGY

1.  The energy that equals the sum of object kinetic energy and the potential energy

HEAT ENERGY

1.  The energy that flows spontaneously from the hot body to the cooler body

Fahrenheit Scale

1.  A scale of temperature in which the freezing point of water = 32 degree

THERMOMETER

1.  A tool to measure temperature

TEMPERATURE

1.  A measure for the average kinetic energy of molecules.

INTERNAL ENERGY

1.  Sum of the kinetic energy and the potential energy of the substance molecules

JAMES JOULE

1.  A scientist who measured the mechanical equivalent of heat

Specific heat capacity of a substance

1.  The quantity of heat needed to raise the temperature of the whole body by one Kelvin

Latent heat of fusion of a substance

1.  The quantity of heat needed to convert 1 kg of the substance from the solid state into the liquid state without a change

      in its temperature.

Freon

1.  A liquid of low boiling point used in cooling systems

compressor

1.  Pipes at the fridge back to get rid of heat

Latent heat of vaporization of a substance

1.  The quantity of heat needed to convert 1 kg of the substance from the liquid state into the vapour state without a change

       in its temperature.

1.  The work is scalar quantity

Because it's the result of the dot product of the force and displacement

1.  We can not add or subtract work and force

Because they have different units ( joules and Newton (

1.  Mass is fundamental, scalar physical quantity.

Because it can not be derived from other quantities, and it is completely described

by knowing its magnitude only.

1.  No measurement can be done with 100% accuracy.

Because of errors:  1- error due to  2- error due to environment as temp. Humidity.

3- Human error in reading

1.  Area, velocity, pressure and density are considered derivable. Physical quantities, not fundamental ones.

Because they are derived from more than one fundamental quantity.

1.  The acceleration of a body moves with uniform velocity in st.line equals zero.

Because the acceleration = vf - vi / t  , and since the velocity is uniform  

so = vf - vi = 0 , and a = zero.

1.  Although a body moving in a uniform circular motion is affected by a centripetal force towards the center, it never gets closer to the center of the circle.

Because the centripetal force acts towards the center of the circle in the normal direction to the displacement

1.  At curves, the motorbike rider tilts his bike and body towards the center of the circular path.

To generate a force normal to the direction of motion. Thus, the direction of motion is changed and the racer moves in a circular path.

1.  When a car moves in a road curve, it maintains its curved path and doesn’t skid

Because the centripetal force acting on the car is normal to the direction of the displacement which maintains its curved path

1.  It is dangerous to move at high velocities in curves of roads.

Because the centripetal force is directly proportional to the square of velocity

1.  Potential energy of water is greater at the top of waterfall than that at the bottom.

Because the P.E is directly proportional to the height

1.  Gaps are left when designing bridges and railways.

Because metals contract by cooling and expand by heating

1.  Velocity is a derived quantity.

Because it's derived from basic physical quantities v = d / t

1.  An object may have acceleration although it moves at constant speed.

Because the velocity may change direction as in circular motion

1.  Potential energy of water is greater at the top of waterfall than that at the bottom.

Because the P.E is directly proportional to the height

1.  Drivers should slow down speed in curved road.

Because the centripetal force is directly proportional to the square of the speed

1.  When two bodies of equal shape and volume but different in mass, are dropped from high, they hit the ground at the same instant.

Because the two bodies traveled the same distance with the same gravitational

acceleration due to a gravity and starting from rest, so they have the same final

velocity and take the same time to reach the ground.

1.  ) A free falling body is a typical example for a motion with uniform acceleration (neglecting the air resistance )

Because at any instant , the rate of change in velocity (Δv/ Δt ) is constant, and equals the acceleration due to gravity "g".

1.  The (displacement - time) graph of a body moves with uniform velocity is a straight line.

Because at any instant, the rate of change in displacement ( Δ d / Δ t  ) is constant

and equal the slope of the graph line.

1.  The motion of "Moon" is a "periodic motion".

Because this moon repeats its motion a round earth at equal time intervals.

1.  Displacement" is a vector, while "Distance" is a scalr physical quantity

Because "Displacement" is described by its magnitude and direction, but "Distance"

is totally described by its magnitude only.

1.  The acceleration of a moving body can be positive or negative.

Because some bodies move in a way such that their final velocities is larger than

their initial ones, so they have a positive acceleration others have final velocity smaller than the initial one, they move with a negative acceleration, this can be cleared from :   a = vf - vi / t

1.  A vertically projected body from the surface of earth returns back to earth with the same velocity if the air resistance is negligible.

1.  The passengers of a bus tend to fall forwards when the bus suddenly stops

Because the passengers try to mentian there state of motion by inertia.

1.  Two or more forces may act on a body without changing its state of motion.

Because the effect of one force is canceled by the other one, giving a resultant force

equals to zero.

1.  Newtons first law can be called "the law of inertia.

Because the inertia is the most important result taken from this law.

1.  It is easier to stop a moving body than stopping a more massive body moves with the same velocity.

Because the smaller body has a smaller inertia, so it can be stoped easly, while the

massive one has a larger inertial, so it can resists more stopping it.

1.  The weight of a body has a greater magnitude than its mass.

Because when calculating the weight, the mass is multiplied by 'g".

1.  The weight is measured in Newton.

Because weight is the force of gravity acting on the bdoy = mg in Newton

1.  Acceleration due to gravity varies from one planet to another.

Because it depends on the mass of the planet and its radius  ,

1.  The centripetal force acting on a body rotaitng in a circular orbit does no work.

Because the direction of motion is always perpendicular to the direction of force

1.  Increaseing the height of a body increases its P.E.

because P.E = m g d.

1.  The potential energy of a dropping body decreases while its kinetic energy increases

Because as the body drops, some of its P.E changes to K.E.

1.  As the velocity of a moving body increases its K.E. increases.

1.  Escape velocity of the satellite does not depend on the mass of the body.

Because

1.  Satellites are considered as free falling bodies.

Because they move in a circular bath under graivtational force of Erath but never reaching its surface.

1.  Water is not used in liquid thermometers.

Because of its irregular expansion with heat

1.  The temperature is not changed on melting.

because the gained energy is used to break bonds between molecules so, kinetic energy and temperature are kept constant

1.  The heat absorbed to change water at 100 o c to vapour increases as the mass of water increases

because the heat needed to evaporate water at 100 o c is directly proportional to the mass of water used.

1.  The heat capacity of a body can't be taken as a physical property for a certain material.

Because it depnds on the mass of the body.

1.  The temeprature of water is not raised by the same degrees as sand beach at noon, though both are exposed to sun for the same period time.

Because the S.H.C. of water is much greater than that of sand beach.

1.  Living creatures can resist the change in temeprature of the surrounding environment

Because living creatures contain a large water content in their bodies, which makes their

heat capacity large enough to resist the temeperature changes.

1.  The direction of force is in the same direction of motion.

The magnitude of velocity increases & its direction does not change

1.  The direction of force is in the opposite direction of motion.

The magnitude of velocity decreases & its direction does not change

1.  The direction of force is normal to direction of motion.

The direction of velocity changes and its magnitude does not change

1.  The centripetal force acting on a body is removed

the body will move at uniform velocity in straight line in the direction of the tangency

1.  The satellite stops and its velocity becomes zero:

It would fall in a straight line towards the earth and fall onto it.

1.  The gravitational force between the earth and the

      satellite vanishes:

The satellite moves in a straight line along the tangent to the circular path, and move getting away from the Earth.

1.  The slope of line in the graph between square of speed on y-axis and reciprocal of mass on x-axis equals 10 J.

This mean that the kinetic energy is 5 j

1.  A body moves at acceleration of (3 m/s2)

The velocity of the object increases by 3 m/s every second.

1.  Specific heat of water is 4200 J/kg. K?

the quantity of heat needed to raise the temperature of 1 kg of

the water by one Kelvin. Is 4200 J

1.  An object has potential energy of 200 J?

The stored energy in the object due its position is 200 J

1.  Free fall acceleration is 9.8 m/s2?

The velocity of the object that falls freely increases by 9.8 m/s every second.

1.  Latent heat of fusion of ice is 3.3 x 105 J/kg?

The quantity of heat needed to convert 1 kg of ice from the solid state into the

liquid state without a change in its temperature is 3.3 × 105 J

1.  Drying clothes.

Skidding of objects away from the circular path when the centripetal force is too weak to keep them in the path

1.  The electric resistance thermometer.

The electric resistance of a resistor changes regularly in platinum thermometer with temperature

1.  Thermometers?

based on selecting a substance with a physical property that changes regularly with the change of temperature

1.  The refrigerator?

Liquids absorb heat energy when converted into vapor; on the other hand heat is released when vapor is converted into liquid

1.  Mercury thermometer?

liquid length changes with temperature in liquid thermometer.

Exam2

The Physical Quantity

The international Unit

1 Length (L)

Meter (m)

2 Mass (M)

Kilogram (kg)

3 Time (T)

Second (s)

4 Electric Current Intensity (I)

Ampere (A)

5 The Absolute Temperature (T)

Kelvin (K)

6 Amount of Material (n)

Mole (mol)

7 Luminous Intensity (Iv)

Candela (cd)

Radian for the angle measure

Steradian for the solid angle measure.

Laws of conservation of Energy and Mechanical energy

The physical

quantity

Its relationship

to other quantities

The dimensional

formula

Unit of

measurement

Area

A = Length × width

L × L = L2 

m2

Volume

V= Length × width × height

L × L × L = L3 

m3

Velocity

v =Displacement/Time

L/T= LT -1

 m / s

Density

ρ = Mass / Volume

M / L3 = ML-3

kg/ m3

Acceleration

a = Change of velocity / Time

LT -1 / T= LT -2

m/s2

Force

F = mass × acceleration

M × LT -2= MLT -2

Newton (N)