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