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60 KMPH TIME = 10 MIN = 10/60 hours = 1/6 hours  distance = speed * time = 60 * 1/6 = 10 km

y= displacement/timeaccleration =velocity/time

of the crane + WEIGHT of the load = 500 + 300 = 800 kggravitational FORCE due to the weight = 800 * g =  800 * 10  NEWTONS.     Resistance to lifting action of the crane  like friction etc. = 1,200 N  Total force needed to lift the load with a velocity 0.2 m/s = 8,000 + 1,200 Newtonspower needed to lift the load with a velocity (uniform)      P = F * V  =  9, 200 N * 0.2 m/sec =  1, 840 Watts

+ 30 cmLet the refractive index of glass μ_g Liquid of refractive index  μ_l = 1.5   when in air,  the focal length of the DOUBLE convex lens is GIVEN by : the lens MAKER's formula:  1 / f_air = 1/30 = (μ_g - 1) 2 / R ,      R = radius of curvature of the lens surface     1/30 *= (μ_g - 1) 2 / R     μ_g - 1 =  R / 60      --- (1)when immersed in the liquid :        1/f2  = 1/120 = (μ_g / μ_l  - 1) 2 / R         (μ_g /1.5  - 1) = R /240      -- (2)         μ_g  - 1.5 = R / 160        -- (3)            subtract (2) from (1),             0.5 = R/60 - R /160 = R /96          R = 48 cm           μ_g  = 1 + 48/60 = 1.8  as per  (1)                  μ_g / μ_l = 1.8/1.5 = 1.2            critical angle between glass and the liquid :  Sin⁻¹  1/1.2 = Sin⁻¹ 0.833             = 56.44 deg.

ement is the SHORTEST distance b/w final and INITIAL point and distance is the ACTUAL path covered by moving body.When a body moves in a straight line then their distance and displacement would be same.If body moves in another trajectory (straight line path) then displacement would be LESS than actual distance for eg a body moves in circle ,after COMPLETING one circle then its actual path covered(distance) would be 2πr and shortest distance b/w initial and final point (displacement) would be zero.

velocity means the total displacement divided by the total time taken.         this is different from the average speed as velocity is a vector.  when we TAKE average we need to take into account the directions of velocity at different times.     if an object travels for time t1  with a UNIFORM velocity   and for time T2  with a uniform velocity  of     then  the average velocity  is      if a person travels for  1 hour  covering a distance of 10 km in a straightline towards the North and then returns along the same STRAIGHT line after 1 hour,  then        v1 vector is 10kmph  towards North.     v2 vector is  10 km ph towards SOUTH.  average velocity is  0.    Average velocity is the net displacement divided by the time interval.

on less QUANTITY      =  PLANE angle          units  degrees or  RADIANS.  symbol  °     = SOLID angle              units STERADIANS  symbol   symbol  sr==============unit less quantity  ---  but dimension  exists for that quantity.     I wonder if there is a quantity like that.  If there is a dimension, that means there is a unit and there is a way of measuring that.  That means there is no such quantity without a unit but with a dimension .

the formula  for a force acting on a CURRENT carrying conductor.              B = magnetic induction = magnetic field strength. Force =  B I L      IE.,  current = I    length  = L  force = newtons.                           let dimensions of current be [ A ]  M L T⁻² =  B  A  L  B = [ M T⁻² A⁻¹ ] =========================we have the formula for magnetic field strength at a POINT d distance AWAY from a current carrying conductor  as :     B = μ₀ I / (2 π d)        this is found by Ampere's circuital law.        μ₀ =  Newtons/Ampere²      B = M L T⁻²  A⁻²   * A  L⁻¹ dimensions      = M T⁻² A⁻¹ units         =  Tesla  or  kg / sec²-Amp        or  Newtons/Amp-meter

t ) =  2  Sin 3.14 x    Cos  100 * 3.14 t       x and y are in meters  and t is in seconds.we use the formula in trigonometry  2 Sin A Cos B = Sin (A+B)  + Sin (A-B)  y (x, t)  =  2  Sin (π x)     Cos (100 π t)                 =  Sin (πx + 100πt)    +    Sin  (πx - 100 πt)                 =  Sin (πx + 100πt)    -    Sin  (100πt  -  πx )                 =  Sin (100 πt + πx)   +  Sin  (100 πt  -  πx + π)GENERAL formula  for a standing wave :  y (x, t) = A Sin (ω t - k x + Ф)  these are the component waves which are PART of the stationary wave.component wave 1:    y1 (x,t)  =  sin (π  x  +  100 π t)       angular frequency = ω    = 100 π  radians/sec      frequency = f  = 50 Hz = ω/2π              Time period: 1/f = 0.02 Sec.       Amplitude = A = 1 m       wave number  k =  - π  rad/meter                       we have formula   ω = k V           velocity  v =  ω / k  = - 100 meters/sec          wavelength λ =  v / f  =  100/50  meters =  2 meters  this component of the wave is traveling in the negative x direction. so its velocity is negative. ==========================component wave 2:    y1 (x,t)  =  sin ( 100 π t - π x +  π )       angular frequency = ω    = 100 π  radians/sec      frequency = f  = 50 Hz = ω/2π              Time period: 1/f = 0.02 Sec.       Amplitude = A = 1 m       wave number  k =  π  rad/meter                       we have formula   ω = k v           velocity  v =  ω / k  = 100 meters/sec          wavelength λ =  v / f  =  100/50   meters =  2 meters   INITIAL phase angle = π radians this wave is traveling in the positive x direction.  so  k and v are positive.But the waves are have a phase difference also.

a form of energy that causes the SENSATION of hotness or coldness.The energy transferred from one body to ANOTHER when in contact due to temperature differences is called HEAT.Heat ALWAYS transfers from a hot body to a COLD body.The amount of heat depends on the amount of matter present in a body.Heat and temperature are not same.

m/sec²t = 10  secondsthe CAR STARTS from rest  ,  so  u = 0.the equation of motion is       s =  u t + 1/2  a t²            =  0 +  1/2  4  10²  meters           =  200  meters

olley has an acceleration  a =  2 cm / sec²      down the INCLINED plane.    its initial velocity  is    U =  0 m/sec.  as it STARTS from rest.   v =  u  +  a  t    =  0 + 2  * t          =  2 *  3  =  6   m /sec     this velocity is along the inclined plane direction.we need to specify the direction as velocity is a vector quantity.

kmph  = 90 * 5/18 m/sec = 25 m/seca = -0.5  m/sec²v = 0  as the train COMES to rest.the equation of motion is      v²  =  u² +  2 a s      0  =  25²  -  2 * 0.5 *  s             s =  625 METERS

/SEC  as it STARTS from REST.   a =  0.1  m/sec²  v =  u +  a  t    =    0.1 t    meters/sec  s =  u t + 1/2  a  t²   =  0.05 t²    meterswe can calculate the speed and DISTANCE travelled after a time interval of t seconds,  if we know  the VALUE of  t.

g the force acting as TENSION in a string;Force, F = 500Nlinear MASS DENSITY, μ = 0.25 kg/mv = ?

v=0 and U is negative⇔v=u + gt⇔so time is 0.02 seconds0= - 5 + (-10) * TWE KNOW that v^2-u^2=2as or 2ghso 0² - (- 5)² = 2 * (10) * h⇒h = 1.25m

unding air become warm when vapour PHASE of water condenses.2)vapour phase of water are the slower moving molecules in the air.3)removal(CONDENSATION) of slower moving molecules from the surroundings INCREASES the AVERAGE kinetic energy of the REMAINING molecules4) hence, the warming.

virus = 4×10⁷ kg per kilomoleso mass of 1000 moles virus = 4×10⁷ kgso mass of 1 MOLE virus = 4×10⁷/1000 =  4×10⁴ kgmass of virus in 1CC tobacco, = 0.1mg0.1mg = 1×10⁻⁷ kg4×10⁴ kg contains 1 mole of virus1 kg will have = 1×10⁻⁷ kg will have = number of viruses in 1 mole = 6.022×10²³ virusesnumber of viruses in  mole = So number of viruses PRESENT in 1 cc will be 1.505×10¹².

ys of light strikes a plane surface(mirror) it is REFLECTED in a particular and straight manner it is known as REGULAR reflection.When rays of light strikes a ROUGH surface(road,ETC.) it is not reflected in a particular way and it is in a scattered manner. This is known as irregular reflection.

r of collision per unit TIME will increase.Temperature always increase randomness.As we increase temperature ,then we will provide energy to MOVING particle.That energy is USED to increase its KINETIC energy.Hence its no. of collision per unit time  will increase.

ave a displacement s as          s  =  u  t  + 1/2 a t²    s = DISTANCE or displacement after  time t SEC.  u  = INITIAL velocity    m/sec   a = UNIFORM acceleration  over time  t    of  m/sec/sec  v = velocity of the particle at time t.then  we have    v =  u +  a  tthe graphs for a uniform    POSITIVE acceleration are  shown  along with the graphs for a uniform velocity.   example acceleration  =  5 m/sec/sec            u = 10 m/sec

ead sea is much below the sea level, the ATMOSPHERIC pressure is more at that level than NORMAL atmospheric pressure at sea level. Since, BOILING point of WATER increases with increases in AIR pressure, the boiling point will increase.

g mass system  is CHARACTERIZED by the equation of motion:        m a = F = m d² X / d t² = - k x                      d² x/ d t² = - k/m  x  = - ω₀² xthe solution for displacement at time t is given by  :                     x = A Cos (ω₀ t + Ф)   ω₀ is the natural frequency of the system for simple harmonic motion.         =  √(k/m) = √(16/1) = 4 rad /SEC.      angular frequency is 4 rad /sec.  A = AMPLITUDE of the vibration = 0.20 metes.  Ф = initial phase of the system, given by          Cos Ф = x₀ / A ,  where x₀ = the position of mass from the mean position when the oscillation has started.      displacement x = A Cos (ω₀ t + Ф)   differentiate :  dx/dt = v = velocity of mass m at time t          v = - A * ω₀  sin (ω₀ t + Ф)    v = -  0.20 * 4 Sin (ω₀ t + Ф)        v = dx/dt = - 0.80 Sin 4 t      if  the initial phase = 0°.

acement is the shortest DISTANCE from the initial to the final POSITION of a POINT.

s STEALTH Fighter reveals NAZI Germany's top-secret development of radar-evading technology.In the final months of World War II a jet powered flying wing made its first test flight from a REMOTE airfield deep inside Nazi Germany. Generations ahead of its time, the Horten 229 had been designed to be a lethal fighter-bomber and more importantly, virtually undetectable to ALLIED radar. Had Reimar and Walter Horten designed the world’s first stealth fighter? Hitler's Stealth Fighter goes behind the scenes with an elite group of aerospace engineers and stealth experts from Northrop Grumman as they build a full-scale model of the sinister bat wing fighter. Once complete, go where cameras have never been ALLOWED as the stealth's Northrop team test the Nazi fighter’s capability at their remote Tejon Radar Range. After decades of debate and speculation the mystery of the Horten 229’s stealth capability is finally put to rest.

of wire V = length L * area of cross SECTION A         A = V/Lρ = resistivity of the material.Resistance of a wire R = ρ L / A = ρ L² / V         L² =  V R / ρ  = 3 m³ * 3 Ω /ρ       L = 3/√ρ the OPTION is B.

kgSpring restoration force F = - k x ,    k = 80 N/mDamping force  F_d = -b v  ,    where  b = 4 N-sec/meter     F = - k x - b v      --- (1)     m a = m d² x / d t²  = - k x - b v       d² x /d t²  = -k/m x - b/m dx/dt            --- (2)   This is the equation of motion in the form of DIFFERENTIAL equation.            let     x = A e^{-a x}  Sin (ωt+Ф)      --- (3)                                 we need to determine A, a, and ω.  differentiate two times:         dx/dt = - a A e^{-a x} Sin ωt + Aω e^{-a x}  Cos ωt        -- (4)                 = A e^{-a x}  [ - a Sin ωt + ω Cos ωt ]       d² x/d t² =  a² A e^{-a x} Sin ωt - a A ω e^{-a x} Cos ωt                              - Aaω e^{-a x} Cos ωt - Aω² e^{-a x} Sin ωt                = (a² - ω²) A e^{-a x} Sin ωt  -  2 A a ωe^{-a x} Cos ωt        ---- (5)  -kx/m - b/m * dx/dt  = -k/m A e^{-a x} Sin ωt  - b/m A e^{-ax} [- a Sin ωt + ω Cos ωt ]                        = A e^{-ax} Sin ωt [ -k/m + ab/m ] - bω/m A e^{-ax} Cos ωt    --- (6)COMPARE equations (5) and (6), we get :           (ab-k)/m = (a² - ω²)    -- (7)           2 a = b/m     =>     b = 2 a m         -- (8)                  =>  2 a² - k / m = a² - ω²         =>  ω² = (k/m  - a²)    x =  A e^{- a x }  Sin [ √(k/m - a²) t  + Ф ]===========================m = 0.2 kg ,    k = 80 N/m    and    b = 4 N-sec/m                   b = 2 a m    =>  a = 10 units  angular frequency ω = √ (k/m - a²) = √(400- 100) = 10√3 rad/sec     frequency = 5√3/π  Hz     and  time period = T = 1/f = π /(5√3) sec = 0.362 secThis is the dampened frequency of the spring mass system.Natural frequency = ω₀ = √(k/m) = √(80/0.2) = 20 rad/sec===============================when a force of  F = 10 Cos 10 t  = F₁ Cos (ω₁t) s applied, The natural frequency of the force and the system are different.  This is a case of forced oscillations.  net force = m a = - k x - b v + 10 Cos 10t      --- (9)      m d²x/dt² = - k x - b dx/dt + 10 Cos 10t     steady state response :  x = a Cos (ω₁ t - Ф),  where,         ω₁ = frequency of the EXTERNAL force = 10 rad/sec.       so frequency = f₁ = 10/2π = 5/π Hz  and the time period T₁ = π/5 Sec.       ω₀ = natural freuency of the spring with out damping or external force = √(k/m)             = 20 rad /sec          a = AMPLITUDE =           Ф = phase =

the capacitor is charged to Q₀  at  t= 0.We have  L = 10 mH ,     C = 1 μF    ,     R = 0.4 ΩWhen at t =0, the circuit with L , C, and R is closed, then the capacitor STARTS to discharge.  The current starts to flow in inductor and stores energy in it.  Some energy starts dissipating through  R.sum of  potential diff, is 0 in the circuit.  let I be the current in the circuit.          L d I / dt  + Q/C  + R I  = 0          differentiate wrt t, and divide by L      d² I /d t² + I / LC + R/L  d I / dt = 0            ---- (1)   let  b = R = 0.4Ω ,    ω₀² = 1/LC  =  k/m,   so  k =1/C = 10⁶ F⁻¹  ,and    m = L = 10 mH   So we have  ω₀ =  10⁴ rad/sec    ,  f = 10⁴/2π  Hz then        d² I/ dt² +  b/m  d I / dt  +  ω₀²  I  =  0        this is the equation.              This looks exactly like the equation for a damped oscillator, with a natural frequency = ω₀.   we know the solution :  I (t) = I₀  e^{- R/2L t }  Sin (ω' t + Ф')         where    ω'  =  √[ ω₀² - (R/2L)² ]  = √ [ 10⁸ - 20² ]  = 9999.98 rad/sec           as   R/2L is  < <  ω₀,  the circuit will OSCILLATE as a slow damped circuit.                   (condition :  R < 2 √[L/C]  same as above)      So  I (t) = I₀  e^{- R/2L t }  Sin (ω' t + Ф')                          I (t = 0)  = I₀ Sin Ф'    where    I₀ =            Cos Ф' = b/(2m ω₀) =  R / (2 L ω₀)  = 20/10000 = 0.002                 Ф' = 1.568 radians  or  89.88 deg.======Quality factor of the circuit is =  Qf =  √[L/C] / R  =  ω₀ / (b/m)  = ω₀ / (R/L)           =  250 approximatelyQf  gives an indication of  number of - minimum - cycles that oscillations will take place, before the amplitude becomes low.========================      d Q(t) / dt  =   I (t) = I₀  e^{- R/2L t }  Sin (ω' t + Ф')we use the integration by parts:  u = e^{- R/2L t }        V ' = Sin (ω' t + Ф')                v = - 1/ω'  Cos (ω' t + Ф')  Q(t) = - 1/ω'  e^{- R/2L t } Cos(ω' t+Ф') -  R/(2Lω')   integral  e^{- R/2L t } Cos (ω' t + Ф')        = - 1/ω'  e^{- R/2L t } Cos(ω' t+Ф') - R/(2Lω')  [ e^{- R/2L t } Sin (ω' t + Ф')                        -  R/(2Lω')  integral e^{- R/2L t } Sin (ω' t + Ф')  ]        =  - 1/ω'  e^{- R/2L t } Cos(ω' t+Ф') - R/(2Lω')  e^{- R/2L t } Sin (ω' t + Ф')                      + R²/(4L²ω'²)  Q(t)Q(t) [ 1 - R²/(4L²ω'²) ]  = - 1/ω'  e^{- R/2L t } Cos(ω' t+Ф') - R/(2Lω')  e^{- R/2L t } Sin (ω' t + Ф')Q(t) = - 1/ω'  e^{- R/2L t } [ Cos(ω' t+Ф') + R/(2L) Sin (ω' t + Ф') ] / [ 1 - R²/(4L²ω'²) ]Q(0) =  - 1/ω' [ Cos Ф'  + R/2L Sin Ф' ] / [ 1 - R²/(4L²ω'²) ] we want  time  t  such that  the amplitude is HALF of Q(0).

take a spring mass system with a natural frequency ω0. m = mass of the body oscillatingSpring restoration force F = - k x ,      k = spring constant.Damping force  F_d = - b v  ,    where  b = damping factor.x = displacement.v = velocity of mass.ω₀ is the frequency of the spring mass when there is no damping.  Only force is spring force.  so,      m d² x / d t²  = - k x    has the solution:                      x = A0 Sin (ω₀ + Ф₀)             --- (0)                       and  ω₀ = √(k/m)       or  ω0² = k/m     ---- (12)===========================    net force acting on mass m is:   F = - k x - b v      --- (1)              The minus sign is because spring restoration force is OPPOSITE to displacement direction and the damping force is in the direction opposite to velocity.               m a = m d² x / d t²  = - k x - b v               d² x /d t²  = -k/m * x - b/m * dx/dt            --- (2)   This is the equation of motion in the form of differential equation. The general solution for the above differential equation is in the following form:           let     x = A_t e^{-at}  Sin (ω' t + Ф')      --- (3)                                 we need to determine A_t, a, and ω'.  differentiate two times:         dx/dt = - a A_t e^{-at} Sin (ω't+Ф')+ + A_tω' e^{-a x}  Cos (ω't+Ф')     -- (4)                 = A_t e^{-at} [ - a Sin ω't + ω' Cos ω't ]      d² x/d t² =  a² A_t e^{-at} Sin (ω't+Ф') - a A0 ω' e^{-at} Cos (ω't+Ф')                              - A_t a ω' e^{-at} Cos (ω't+Ф') - A_t ω'² e^{-at} Sin (ω't+Ф')            = (a² - ω'²) A_t e^{-at} Sin (ω't+Ф')  -  2 A_t a ω'e^{-at} Cos (ω't+Ф')  --(5)Find the RHS of equation (2)   -kx/m - b/m * dx/dt       = -k/m A_t e^{-at} Sin(ω't+Ф') - b/m A_t e^{-at} [- a Sin(ω't+Ф') + ω' Cos(ω't+Ф')]       = A_t e^{-at} Sin(ω't+Ф') [ -k/m + ab/m] - bω'/m A_t e^{-at} Cos(ω't+Ф') --(6)Compare equations (5) and (6), we GET :           (ab - k) / m = (a² - ω'²)    -- (7)            a = b/(2m)     =>     b = 2 a m         -- (8)         =>  2 a² - k / m = a² - ω'²         =>  ω'² = ( k/m  - a²)  = (ω₀² - a²) =  [ω₀² - b²/4m² ]            =>   ω' = √[ω₀² - b²/4m² ]           --- (9)  also the phase angle of the damped oscillation is :          Cos Ф' = a/ ω₀ = b/(2m ω₀)         Tan Ф' = ω'/a = √[ 4m² ω₀²/ b² - 1 ] = √[ ω₀²/a² - 1 ]      --- (10) in terms of initial value of  displacement x = x₀ at t = 0sec and initial velocity v₀ = dx/dt at t = 0sec of the damped oscillations,          Tan Ф' =  ω' x₀ / [ v₀ +  a x₀ ]          x =  A_t  e^{ -bt /(2m) }  Sin [ ω' t  + Ф' ]      -- (11)                      A_t  = x₀ Cosec Ф'    from EQ (3)                    =  √ [ x₀² + (v₀ +  a x₀)² / ω'²  ]

n of motion and force:           F = m a = m d²x/dt² = - k x                      d²x/dt² = - k/m x      let x = A Sin (ωt + Ф)             then  d²x/dt² = - A ω² Sin(ωt+Ф) = - ω² x       k = 116 N/m  or  16 N/m  ???      which ONE ?       m = 0.1 kg       A = 0.20 metersSHM :  angular frequency = ω = √(k/m) = √(116/0.1) = 34 rad/sec                         if  k = 16 N/m,    ω = √160 = 4√10 rad/sec   ==========     x = A Sin (ωt + Ф)          = displacement from the mean POSITION     v = velocity of the particle executing the SHM     v = dx/dt = A ω Cos (ω t + Ф)            v  = ω  √A² - x² )  = ω A  √[1 - x²/A² ]====================   x = 1.0 m      this value is not possible, as  amplitude is 0.20 m.  SO x has to be less than 0.2 m.  Is it 0.1 meters ?      x has to be less than or EQUAL to amplitude.   v = 4√10 rad/sec * √[0.2² - 0.1²] meters = 2.19 m/sec========================Energy of the spring MASS system :        = 1/2 m v² at the mean equilibrium position , as x = 0  and PE = 0         = 1/2 k A²  at the extreme position when x = A, as  v = 0 and KE = 0.     = 1/2 * 0.1 kg * 0.20² = 0.002 Joules

istence in a WIRE is DIRECTLY PROPORTIONAL to LENGTH of wire.

vity values are USED to COMPARE the conducting properties of different materials.resistance, is independent of the DIMENSIONS of the SAMPLE.

F = 20 NewtonsMass = m = 4 kginitial velocity u = 0 ACCELERATION a = force / mass = F / m         = 20 / 4 = 5 meters/sec²velocity v = u + a t     v = 0  + 5 m/sec² * 10 sec = 50 m/sec  During the first 10 SECONDS when the force is acting on the body, the body ACCELERATES continuously.  That is its speed increases every instant.  At 1 sec its speed is 5 m/s,  at 2 sec, its speed is 10 m/s,  at 3 sec, its speed is 15 m/s ....   when the force ceases to act at 10 sec, then the body CONTINUES to MOVE along the straight line (as per the 1st law of Newton).  it moves with a constant velocity of 50 m/sec.  this is the inertia of motion.

e a variety of ultrasonic ranging (ECHOLOCATION) techniques to detect their prey. They can detect frequencies beyond 100 kHz, possibly up to 200 kHz.[6]Many insects have good ultrasonic hearing and most of these are nocturnal insects listening for echolocating bats. This includes many groups of moths, beetles, praying mantids and lacewings. Upon hearing a bat, some insects will make evasive manoeuvres to escape being CAUGHT.[7] Ultrasonic frequencies trigger a reflex action in the noctuid moth that cause it to drop SLIGHTLY in its flight to evade attack.[8]Tiger moths also emit clicks which may disturb bats' echolocation,[9][10] but may also in other cases evade being eaten by advertising the FACT that they are poisonous by emitting sound.[11][12]

r still or dark water collected in a vessel was considered or used as mirrors by ancient people. Then as days passed obsidian mirrors came in to existence followed by metal coated glass mirrors this led to discovery of metal coated spherical or parabolic mirrors.  A spherical mirror is a mirror which has the shape of a piece cut out of a spherical surface. There are TWO types of spherical mirrors: concave, and convex. These mirrors are also known as parabolic mirrors discovered in mid9th century Ibn al haytham and Ibn sahl.parabolic mirrors were described in classical antiquity written by mathematician-Diocles . In addition to these RESEARCHES Ptolemy also carried out experiments with curved polished iron mirrors and discussed about convex spherical and concave spherical mirrors in his book OPTICS.   Inspite of these researches finding the focal length of spherical mirror was a though task but finally Ibn al Hay tham got a break through by finding out the focal length of curved surfaces USING the laws of reflection.he stated that “All the reflected rays of a mirror converge or diverge and meet at a point known as focus and the distance between focus and pole of mirror is known as focal point of mirror.’’Also many scientists came to a conclusion that spherical mirrors can be divided into concave and convex mirrors.   Spherical mirrors   Concave mirrors   Convex mirrors The invention of concave and convex mirrors led to many changes and have become a part of our life .

a fundamental difference between temperature and heat. Heat is the amount of energy in a SYSTEM. The SI units for heat are Joules. A Joule is a Newton times a meter. A Newton is a kilogram-meter per second squared. Heat is transferred through radiation, conduction and convection. The amount that molecules are vibrating, rotating or moving is a direct function of the heat CONTENT. Energy is transported by conduction as molecules vibrate, rotate and/or collide into each other. Heat is moved along similar to DOMINOS knocking down their neighbors in a chain reaction. An increase of electromagnetic radiation into a system causes the molecules to vibrate, rotate and/or move faster. With convection, higher energy molecules are mixed with lower energy molecules. When higher energy molecules are mixed with lower energy molecules the molecular motion will come into equilibrium over time. The faster moving molecules will slow down and the slow moving molecules will speed up. Temperature is the MEASURE of the AVERAGE molecular motions in a system and simply has units of celsius,KELVIN Notice that one primary difference between heat and temperature is that heat has units of Joules and temperature has units of (degrees F, degrees C, or K). Another primary difference is that energy can be transported without the temperature of a substance changing (e.g.latent heat), ice water remains at the freezing point even as energy is brought into the ice water to melt more ice). But, as a general statement (ignoring latent heat), as heat energy increases, the temperature will increase. If molecules increase in VIBRATION, rotation or forward motion and pass that energy to neighboring molecules, the measured temperature of the system will increase.NOTE:THE TEXT IS NOT COPIED FROM ANYWHERE.IF IT HELPS U PLZZZZZZZZ MARK IT AS BST

E DOESNOT HAPPENS ON THE ANT SINCE IT DOESNOT HAVE ANY DISPLACEMENT WHILE IT SIT ON THE BACK OF THE MICE SO      W=F*S        =F*0  [S=0]       =0

ugal force is HELPFUL in SEPARATING BUTTER from MILK.

e traveled = (11200-11185) KM = 15 kmTime taken = 30 MINUTES = 30/60 HR = 0.5 hrSpeed = Distance/Time = 15/0.5 = 30 km/hr