A quantity of steam at 100oC condenses to water at the same temperature by releasing 6.9 x 104J of energy. Calculate the mass of the condensed steam. [specific latent heat of vaporization of eater = 2.3 x 106 J kg-1]
A3.0 x 10-1 kg
B3.0 x 10-2 kg
C3.0 x 10-3 kg
D3.0 x 10-4 kg
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Question 1082
waec2006
The amount of energy required to change a kilogram of ice in water without a change in temperature is
Aheat capacity of ice
Bspecific heat capacity
Cspecific latent heat of vaporisation of ice
Dspecific latent heat of fusion of ice
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Question 1083
waec2006
How long will it take to heat 3kg of water from 28oC to 88oC in an electric kettle taking 6a from a 220V supply? [specific heat capacity of water = 4180 J kg-1K-1]
A120s
B570s
C600s
D836s
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Question 1084
waec2006
The silvered surface in a vacuum flask reduces heat loos due to
Aconduction
Bconvection
Cradiation
Devaporation
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Question 1085
waec2006
The sagging of overhead electrical cables is the consequence of
Alinear expansivity
Bsuperficial expansivity
Ccubic expansivity
Dconductivity
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Question 1086
waec2006
A block and tackle system has six pulleys. a force of 50N applied to it lifts a load of weight W. If the efficiency of the system is 40%, calculate W
A300N
B200N
C140N
D120N
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Question 1087
waec2006
The velocity ratio of an inclined plane, inclines at an angle \(\theta\) to the horizontal can be expressed as
A(sin \(\theta)^{-1}\)
B\(\sin \theta\)
C(cos \(\theta)^{-1}\)
D\(\cos \theta\)
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Question 1088
waec2006
The engine of a train produces a force of 3000N when moving at 30.ms-1. calculate the power of the engine
A1.00 x 102W
B3.00 x 104W
C9.00 x 104W
D3.00 x 105W
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Question 1089
waec2006
The potential energy in an elastic string of force constant K which has been extended by X metres is expresses as
A\(\frac{1}{2}k \Box ^2\)
B\(k \Box ^2\)
C\(\frac{1}{2}k \Box \)
D\(k \Box \)
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Question 1090
waec2006
Which of the following statements about the mouth piece of a telephone is correct? It converts sound energy into
Aacoustic energy
Bmechanival energy
Celectrical energy
Dheat energy
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Question 1091
waec2006
A stone of mass 2.0kg is thrown vertically upward with a velocity of 20.0 ms-1, calculate the initial kinetic energy of the stone
A200J
B400J
C800J
D1600J
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Question 1092
waec2006
Which of the following source of energy is renewable?
Apetroleum
Bcharcoal
Chydro
Dnuclear
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Question 1093
waec2006
A force acting on a body causes a change in the momentum of a body from 12 kg ms-1 to 16kg ms-1 in 0.25. Calculate the magnitude of the impulse
A28.0Ns
B20.0Ns
C4.0Ns
D0.8Ns
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Question 1094
waec2006
which of the following statements about simple harmonic motion is correct? The
Atotal mechanical energy is always conserved
Blinear acceleration is directed to any variable point
Clinear acceleration varies inversely with displacement
Dperiod of oscillation varies linearly as acceleration due to gravity
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Question 1095
waec2006
Which of the following quantities is a vector?
Aspeed
Bdistance
Cenergy
Dmomentum
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Question 1096
waec2006
A car accelerates uniformly from rest at 5 ms-2. Determine its speed after 10s
A50.0ms-1
B25.0ms-1
C2.0ms-1
D0.5ms-1
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Question 1097
waec2006
Uniform speed occurs when there is equal change of
Adistance in equal times
Bdisplacement in equal times
Cvelocity in equal times
Dacceleration in equal times
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Question 1098
waec2006
A moving car of mass 800 kg experiences a frictional force of 200N. If it accelerates 2 ms-2, calculate the magnitude of the force applied to the car
A600N
B1000N
C1600N
D1800N
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Question 1099
waec2006
A body is rotating in a horizontal circle of radius 2.5m with an angular speed of 5 rad s-1. Calculate the magnitude of the radial acceleration of the body
A62.50ms-2
B31.25ms-2
C12.50ms-2
D10.00ms-2
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Question 1100
waec2006
An object is said to undergo oscillatory motion when it moves
