2018 - JAMB Physics Past Questions and Answers - page 7

Volume of liquid displaced

 = $\frac{2}{3}$(0.5)${}^3$

  Mass of liquid displaced = mass of floating cube = 75kg

  Density of liquid = $\frac{mass}{volume}$

  = $\frac{75}{(\frac{7}{3(0.5)})}$  × 3

  = 0.9 × 103kgm${}^{-3}$

  R.D of liquid = $\frac{(0.9)}{(1.0)}$ × 103

  = 0.9

V = F × lambda

= 260 × 1.29

= 335.4ms(^{-1})

P = 40W

  R = 90W

  V = ?

  P = $\frac{V^2}{R}$

  V${}^2$ = PR = 40 x 90

  V${}^2$ = 3000

  V = √3600

  V = 60N

Water 1 => M = 150g = 0.15kg,

  θ${}_2$ = 60${}^o$C; θ${}_1$ = θ

  Q${}_1$ = MC (θ${}_2$ – θ${}_1$)

  = 0.15C (60 - θ)

  Water 2 => M = 300g = 0.3kg

  θ1 = 20${}^o$C, θ${}_2$ = θ

  Q2 = MC (θ${}_2$ – θ${}_1$)

  = 0.3C (θ – 20)

  Combine Q1 & Q2, we get:

  0.15C (60 - θ) = 0.3C (θ – 20)

  9 – 0.15θ = 0.3θ – 6

  0.3θ + 0.15θ = 9 + 6

  0.45 θ = 15

  θ = 33.33${}^o$C

Brownian motion: any of various physical phenomena in which some quantity is constantly undergoing small, random fluctuations.

Thermionic emission: thermally induced flow of charge

Nuclear fission: nuclear reaction or a radioactive decay process

Photoelectric emission: emission of electrons or other free carriers when light shines on a material

Y – Ray is a penetrating electro-magnetic radiation.

α – particle is produced in the process of alpha decay.

Neutron is a sub-atomic particle.

Radiation is the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization