[WAEC CHOCK] 2014 Waec Physics Answers (Essay & Obj)

Physics obj:
1-10: DABABACBBB11-20: DCABCBBAAC21-30: ABBCCDCDBB31-40: CBDCBCDDAA41-50: DDBADBDAAB

Physics essay:

NOTE: @ means tita sign.

(2.)
R: (U^2sin2@)/g
78: (30*30 sin2@)/10
0.8667:sin2@
2@=60
@=30

(4.)
young modulus: stress/strain
stress=F/A=35000/4=8750
strain=e/l=0.025/50=0.0005
young modulus=8750/0.0005=17500000

5a)Gas can conduct electricity under lowpressure andhigh votage.

5b)cathode

(7a) The minimum energy of theincident ray of the light must beequal to the work function of thematerial or above the work functionof the metal.

(7b)(i) Polarization.
(ii) Diffraction.

(8a)
(i) Rotational Motion
I* The movement of the blades of a fan.
II* The motion of the wheel of a car.
(ii) Linear Motion
I*The motion of a boy from a point to anotherpoint on a straight line.
II* The motion of a ball on a straight course.

(8b.)AIM: To determine the density of anirregularly shaped solid

APPARATUS: An irregularly shaped solid,a beam balance,a measuring cylinder,aprice of thread

PROCEDURE: Place the irregularly shapedsolid on the beam balance and measuredits mass as mkg and place the solid inthe measuring cylinder that contains water up to say xm^3 with the aid of the thread. Record the new volume of ym^3.

(9)(a) Heat capacity is the quantity ofheat required to change thetemperature of a substance by 1 k or1degree Celsius

(9b) I. It changes the phase

(9d) Given,
mass of pepper soup, m=800g
=0.800kg
Initial temprature of pepper soup,
tita =30degree C
Power of the microwave oven,
P=1200w
Time taken, t =3minutes =3*60s =180s.
Specific heat capacity of pepper soup,
c=4000j/kg k.

(9di)final temperature of the pepper soup,@2=? ,Heat given by d microwave oven= Heatabsorbed by d pepper soup.Pt= mc(@2 - @1),1200 * 180= 0.8
(9Dii) containers with tight-fitting lids arenot suitable for use in microwave cookingbecause there must be room forexpansion which can only be catered forif the lids are not tight-fitted
(9diii) there is dent on the containerbecause the final temperature was solarge compared to the material used inmaking the container,I.e plastic.andplastics are not very good for suchheat.The cooling of the plastic cannot be uniform

Physics essay:
(2.)
R: (U^2sin2@)/g
78: (30*30 sin2@)/10
0.8667:sin2@
2@=60
@=30
(4.)
young modulus: stress/strain
stress=F/A=35000/4=8750
strain=e/l=0.025/50=0.0005
young modulus=8750/0.0005=17500000
5a)Gas can conduct electricity under lowpressure andhigh votage.
5b)cathode
(7a) The minimum energy of theincident ray of the light must beequal to the work function of thematerial or above the work functionof the metal.(7b)(i) Polarization.(ii) Diffraction.
(9)(a) Heat capacity is the quantity ofheat required to change thetemperature of a substance by 1 k or1degree Celsius
(9b) I. It changes the phase
(9d) Given,
mass of pepper soup, m=800g
=0.800kg
Initial temprature of pepper soup,
tita =30degree C
Power of the microwave oven,
P=1200w
Time taken, t =3minutes =3*60s =180s.
Specific heat capacity of pepper soup,
c=4000j/kg k.
(9di)final temperature of the pepper soup,@2=? ,Heat given by d microwave oven= Heatabsorbed by d pepper soup.Pt= mc(@2 - @1),1200 * 180= 0.8(9Dii) containers with tight-fitting lids arenot suitable for use in microwave cookingbecause there must be room forexpansion which can only be catered forif the lids are not tight-fitted(9diii) there is dent on the containerbecause the final temperature was solarge compared to the material used inmaking the container,I.e plastic.andplastics are not very good for suchheat.The cooling of the plastic cannot be uniform - See more at: http://www.nairaguys.tk/forum2_theme_1045793.xhtml?tema=192#sthash.IYiymX1C.dpuf