1997 - JAMB Physics Past Questions and Answers - page 2

Young's modulus = (\frac{F}{A}) (\div) (\frac{e}{L})

= (\frac{20}{8 \times 10^{-7}}) (\div) (\frac{10^{-4}}{3})

= 7.5 x 10¹¹Nm^-2

Volume of water displaced = volume of cube

therefore, 0.1 x 0.1 x 0.1 = 0.001m³

mass of H₂O = 0.001 X 1000

= 1kg

upthrust = mg

= 1 x 10

=10N

Density of liquid = (\frac{1 {\times} 10^3}{2.5 {\times} 2 {\times} 4})

= 50kgm³

pressure heg = 50 x 10 x (\frac{4}{2})

= 1 x 10³Nm^-2

R.d = (\frac{\text {density of petrol}}{\text{density of water}})

0.72 = (\frac{\text{density of petrol}}{1000})

Density of petrol =720kgm³

mass of petrol = 720 x 60 x 10^-3

=43.2kg

(\frac{\theta\ - 0}{100 - 0}) = (\frac{175 - 25}{225-25})

(\theta) = 75.0^oC

(\frac{P_1}{T_1}) = (\frac{ P_2}{T_2})

(\frac{3 \times\ 10^6}{27 + 273}) = (\frac{4 \times\ 10^6}{0 + 273})

(\theta) = 127^oC

Heat energy = Elect. energy

0.5 x 2.3 x 10⁶ = 100t

t = 1.15 x 10⁴s