WAEC PHYSICS 2017 FREE ANSWER

3)
i)Brownian motion
ii)Atomic size
iii)Expansion
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2)
given that U=15m3^-1
R=U* sqr2h/g
h=20m
g=10
R=15*sqr2*20/10
R=15*sqr40/10
R=15*sqr4
R=15*2=30m
R=30m
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5a)
i)force
ii)length
5b)
by increasing the density mosquitoes lavrva than the density of water
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6)
i)Energy efficient- so far the best light for interior lighting
ii)Low production cost (of tubes, not of the ballasts)
iii)Long life of tubes
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12ai)
Nuclear fission is a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy.
12aii)
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un-enriched uranium to be used as nuclear fuel.
12aiii)
Boron rods are used in
nuclear reactors to control the fission rate of uranium and plutonium. They are composed of chemical elements such as boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.
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8b)If their distance and masses are doubled their corresponding force would also be doubled and the work done respectively
I.e.Workdone=Force * distance
Force= Mass * Acceleration
W= Mg * d
     |
Increase
8d (i)pushing someone on a swing.
      (ii)Tuning a radio to a particular frequency.
4)
L1=14cm F1=4N,F2=6N
L2=4cm, Lo=?
Using hooke's law
4/14-Lo*6/4-Lo
4(4-Lo)=6(14-Lo)
16-4Lo=64-6Lo
-4Lo+6Lo=64-16
2Lo=48
Lo=48/2
Lo=24Cm
10a) A wave front is an imaginary  surface passing through the points of a medium oscillatory in phase
2)given that U=15m3^-1
R=U* sqr2h/g
h=20m
g=10
R=15*sqr2*20/10
R=15*sqr40/10
R=15*sqr4
R=15*2=30m
R=30m

 3i) Brownian Motion
II) Atomic Size
Iii) Expansion

5a)
i)force
ii)length

5b)
By increasing the density mosquitoes lavrva than the density of water

6i)Energy efficient- so far the best light for interior lighting.
ii)Low production cost (of tubes, not of the ballasts)
iii)Long life of tubes.

7 )
i ) It requires low voltage sources for it to function
ii ) It cannot be easily broken
iii ) It is cheaper and quite easy to manufacture

8b)If their distance and masses are doubled their corresponding force would also be doubled and the work done respectively
I.e.Workdone=Force * distance
Force= Mass * Acceleration
W= Mg * d
     |
Increase

 8c) -Acceleration due to gravity
- At maximum height, final velocity is zero

8d (i)pushing someone on a swing.

(ii)Tuning a radio to a particular frequency.
12ai)Nuclear fission is a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy.

12aii)a)A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un-enriched uranium to be used as nuclear fuel.

12aii)b)Boron rods are used in
nuclear reactors to control the fission rate of uranium and plutonium. They are composed of chemical elements such as boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.

 10a) A wave front is an imaginary  surface passing through the points of a medium oscillatory in phase