PHYSICS OBJ:
1-10: CCBBCCDBBD
11-20: CBCCADACBB
21-30: BBABDBBDBD
31-40: DBBDDABABC +++++++++++++++++++++++++++++++++++ (1) (a) impulse(I)=F*t F=ma= m(v/t)= M((d/t)/(t)) f=M(l/T)/T)= MLT^-2 I=MLT^-2 * T I=MLT^-1
(b) Acceleration(a)=v/t=(d/t)/t a=d/t^2= L/T^2= LT^-2
(c) WOrk(w)=f*d W=MLT^-2 * L W=ML^2T^-2 ===========================
(2) Velocity(u)=20ms^-1 Angle(tita)=40 degree At maximum height, h V^2=u^2 + 2gh U^2 sin^2 tita+u u= 20^2* (sin 40 degree)^2 u=20^2*(sin 4o degree) u=400* 0.3455 u=138.2ms^-1 =============================
(3) -smoke -aerosol -dust particle ======================
(4) Given flux density(B)=0.217 Force(F)=9.6*10^-12N Speed(v)=? F=Bqv 9.6*10^-12= 0.12* 1.6* V V=(9.6*10^-12)/0.192*10^-19 =50*10^-12+9 v=50*10^7 =5*10^8ms^-1 ==========================
(5) -for exploration of space -it is used for war fare -it is used for launching of satellite ================================
(6) (a)doping is the process of producing an impure semiconductor by adding foreign elements to the pure semiconductor
(b)Doping a semiconductor improves the number of charge carriers =============================
(10a) Critical angle is the angle of incidence in the optically densed medium when the angle of refraction is 90degrees
(10b) Anti-note are created by region of maximum displacement in a wave ================================
(11a) Dielectric strength is the property of an insulating material to retain material to retain electrical properties
(11bi) -Infra-red wave -Geiger muller counter -Scintillation counter
(11bii) Irradiation of solar energy
(11c) Charge(q)=1.0*10^-19C Electric field intensity(E)=1200NC^-1 Weight of the oil drop=? E=F/q 1200=F/1.0*10^-19 F=1200*1.0*10^-19 F=1.2*10^3*10^-19 F=1.2*10^-16N
(11d) R=100ohm, L=0.05H, C=0.25uF V=220v, f=50Hz
(11di) Impedance(z)=sqroot(R^2+(Xl-Xc)^2) Xl=2*pie*fl Xl=2*(22/7)*50*0.05 Xl=15.71ohm Xl=(1/2*pie*fc) Xc=1/78.55*10^-6 Xc=10^6/78.55 =12730.7ohm Z=sqroot(100^2+(15.71^2-12730.7^2) Z=sqroot(10000+2.63*10^16 Z=sqroot(2.63*10^16) Z=1.62*10^16ohm
(11dii) Vrms=IZ I=220/1.62*10^16 =1.36*10^-14
8a) Net force is the resultant force acting on the body
(8b)The principle of conservation of linear momentum states that is an isolated system,the total momentum before colision is equal to the total momentum after collision example:collision of a bullet with a target
(8c) Mass(m)200g=200/1000=0.2kg height(h)=2.0m New height(h)=1.8m Impulse=F*t=m(v-u) I=mgh*t=m(v-u) I=0.2*9.8*(2.0+1.8) I=7.45N
(8d) Given; mass(m)=20g=20/1000 m=0.02kg Frequency(f)=5Hz Distance(x)=10cm=10/1000=0.1m Velocity(v)=200cms^-1=2ms^-1
(i) V=wsqroot(A^2-x^2) V^2=w^2(A^2-x^2) w=2*pie*f=2*3.14*5 w=31.4rad/s 2^2=3.14^2(A^2-0.1^2) A^2-0.1^2=4/985.96 A^2-0.1^2=0.0041 A^2=0.00414+0.01=0.0141 A=sqroot(0.0141) =0.12m
(ii) Maximum velocity(v) V=wA V=3.14*0.12 V=3.768m/s =3.8m/s
(iii) Maximum potential energy P.Emax==1/2MV^2max P>Emax=1/2*0.02*3.8^2 =0.14J
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