/32 Physics Chapter 1 : Topic 1 SI Base Units of Derived Quantities 1 / 32 Which of the following correctly represents the SI base units of force (newton)? A) $\mathbf{kg\ }\mathbf{ms}^{\mathbf{- 2}}$ B) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 1}}$ C) $\mathbf{kg\ }\mathbf{ms}^{\mathbf{- 1}}$ D) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: Force $\mathbf{=}$ mass $\mathbf{\times \ }$acceleration $\mathbf{= kg \times (m}\mathbf{s}^{\mathbf{- 2}}\mathbf{) = kg\ m}\mathbf{s}^{\mathbf{- 2}}$ 2 / 32 The SI base unit of pressure is: A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 2\ }}\mathbf{s}^{\mathbf{- 2}}$ C) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$ D) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: Pressure $\mathbf{=}$ Force / Area $\mathbf{= (kg\ m}\mathbf{s}^{\mathbf{- 2}}\mathbf{)\ /\ }\mathbf{m}^{\mathbf{2}}\mathbf{= kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$ 3 / 32 Which derived quantity has the SI unit $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$? A) Force B) Power C) Pressure D) Energy Reasoning: Energy (joule) $\mathbf{=}$ Force $\mathbf{\times \ }$distance $\mathbf{= (kg\ m}\mathbf{s}^{\mathbf{- 2}}\mathbf{)(m) = kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ 4 / 32 The SI base units of power are: A) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{kg\ }\mathbf{s}^{\mathbf{- 3}}$ C) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}$ D) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: Power $\mathbf{=}$ Energy / time $\mathbf{= (kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}\mathbf{)\ /\ s = kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}$ 5 / 32 Which quantity has the same SI base units as pressure? A) Impulse B) Energy C) Stress D) Momentum Reasoning: Stress $\mathbf{=}$ Force / Area, same definition as pressure, so same units. 6 / 32 Momentum has SI base units: A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 1}}$ B) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ C) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 1}}$ D) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: Momentum $\mathbf{=}$ mass $\mathbf{\times \ }$velocity $\mathbf{= kg \times m\ }\mathbf{s}^{\mathbf{- 1}}$ 7 / 32 The SI base unit expression of density is: A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 1}}$ B) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 2}}$ C) $\mathbf{kg\ }\mathbf{m}^{\mathbf{3}}$ D) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 3}}$ Reasoning: Density $\mathbf{=}$ mass / volume $\mathbf{=}\mathbf{kg\ /\ m}^{\mathbf{3}}\mathbf{= kg\ }\mathbf{m}^{\mathbf{- 3}}$ 8 / 32 Which quantity has SI base units $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$? A) Work B) Power C) Pressure D) Momentum Reasoning: Pressure $\mathbf{=}$ Force / Area $\mathbf{= kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$ 9 / 32 The SI base units of acceleration are: A) $\mathbf{m}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ C) $\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ D) $\mathbf{m}\mathbf{s}^{\mathbf{- 1}}$ Reasoning: Acceleration $\mathbf{=}$ change in velocity per second. 10 / 32 Which of the following is NOT a derived unit? A) Newton B) Joule C) Pascal D) Kilogram Reasoning: Kilogram is an $\mathbf{SI}$ base unit; others are derived units. 11 / 32 The SI base unit of work done by a force is: A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}$ C) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$ D) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: Work $\mathbf{=}$ Force $\mathbf{\times}$ distance 12 / 32 A quantity has units $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}$. It is most likely: A) Pressure B) Momentum C) Power D) Energy Reasoning: Power $\mathbf{=}$ Energy / time 13 / 32 The SI base units of frequency are: A) $\mathbf{s}$ B) $\mathbf{s}^{\mathbf{- 1}}$ C) $\mathbf{kg\ }\mathbf{s}^{\mathbf{- 1}}$ D) $\mathbf{m}^{\mathbf{- 1}}$ Reasoning: Frequency $\mathbf{=}$ number of cycles per second 14 / 32 Which quantity has units $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 1}}$? A) Impulse B) Power C) Pressure D) Energy Reasoning: Impulse $\mathbf{=}$ Force $\mathbf{\times \ }$time $\mathbf{=}\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 1}}$ 15 / 32 Velocity can be expressed as: A) $\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 1}}$ B) $\mathbf{m}\mathbf{s}^{\mathbf{- 1}}$ C) $\mathbf{m}\mathbf{s}^{\mathbf{- 2}}$ D) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 1}}$ Reasoning: Velocity $\mathbf{=}$ displacement / time 16 / 32 Which derived quantity has units $\mathbf{m}^{\mathbf{2}}$? A) Velocity B) Acceleration C) Volume D) Area Reasoning: Area $\mathbf{=}$ length $\mathbf{\times}$ length 17 / 32 The SI base unit expression of volume is: A) $\mathbf{m}^{\mathbf{2}}$ B) $\mathbf{m}^{\mathbf{3}}$ C) $\mathbf{kg\ }\mathbf{m}^{\mathbf{3}}$ D) $\mathbf{m}^{\mathbf{- 3}}$ Reasoning: Volume $\mathbf{=}$ length $\mathbf{\times}$ width $\mathbf{\times}$ height 18 / 32 If force is multiplied by time, the resulting unit is: A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2}}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ C) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2}}\mathbf{s}^{\mathbf{- 3}}$ D) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 1}}$ Reasoning: Force $\mathbf{\times}$ time $\mathbf{=}$ impulse 19 / 32 Which quantity has units $\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$? A) Pressure B) Density C) Acceleration D) Velocity squared Reasoning: ${\mathbf{(m}\mathbf{s}^{\mathbf{- 1}}\mathbf{)}}^{\mathbf{2}}\mathbf{=}\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ 20 / 32 The SI base unit of energy divided by force gives: A) $\mathbf{kg}$ B) $\mathbf{m}^{\mathbf{2}}$ C) $\mathbf{s}$ D) $\mathbf{m}$ Reasoning: Energy / Force $\mathbf{= (kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}\mathbf{)\ /\ (kg\ m}\mathbf{s}^{\mathbf{- 2}}\mathbf{) = m}$ 21 / 32 Which quantity is represented by $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 3}}$? A) Momentum B) Force C) Density D) Pressure Reasoning: Density $\mathbf{=}$ mass per unit volume 22 / 32 The SI base unit of force divided by mass is: A) $\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{m}\mathbf{s}^{\mathbf{- 1}}$ C) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ D) $\mathbf{m}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: $\mathbf{F\ /\ m =}$ acceleration 23 / 32 A quantity has units $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$. Dividing it by time gives units of: A) Pressure B) Power C) Force D) Momentum Reasoning: Energy / time $\mathbf{=}$ power 24 / 32 Which expression correctly represents the pascal $\mathbf{(Pa)}$? A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}$ C) $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2}}$ D) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: Pascal $\mathbf{=}\mathbf{N/m}^{\mathbf{2}}$ 25 / 32 Which SI base unit appears in every mechanical quantity among force, energy, momentum and pressure? A) Kelvin B) Kilogram C) Mole D) Ampere Reasoning: All these quantities involve mass, represented by kilogram. 26 / 32 The unit $\mathbf{kg\ }\mathbf{m}^{\mathbf{2}}\mathbf{s}^{\mathbf{- 2}}$ can also be written as: A) $\mathbf{N\ m}$ B) $\mathbf{N/m}$ C) $\mathbf{N\ s}$ D) $\mathbf{N/m}^{\mathbf{2}}$ Reasoning: Joule $\mathbf{=}$ Newton $\mathbf{\times}$ metre 27 / 32 Which quantity has dimensions involving only length and time but not mass? A) Pressure B) Density C) Force D) Velocity Reasoning: Velocity $\mathbf{=}\mathbf{ms}^{\mathbf{- 1}}$ 28 / 32 The SI base unit of power divided by force gives: A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{m}$ C) $\mathbf{m}\mathbf{s}^{\mathbf{- 1}}$ D) $\mathbf{s}^{\mathbf{- 1}}$ Reasoning: $\mathbf{(kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}\mathbf{)\ /\ (kg\ m}\mathbf{s}^{\mathbf{- 2}}\mathbf{) = m}\mathbf{s}^{\mathbf{- 1}}$ 29 / 32 Which quantity has the most negative power of metre in its unit? A) Force $\mathbf{(kg\ m}\mathbf{s}^{\mathbf{- 2}}\mathbf{)}$ B) Pressure $\mathbf{(kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}\mathbf{)}$ C) Density $\mathbf{(kg\ }\mathbf{m}^{\mathbf{- 3}}\mathbf{)}$ D) Velocity $\mathbf{(m}\mathbf{s}^{\mathbf{- 1}}\mathbf{)}$ Reasoning: Density contains $\mathbf{m}^{\mathbf{- 3}}$, the largest negative exponent. 30 / 32 A student writes the unit of energy as $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}$. What mistake has been made? A) Mass unit is incorrect. B) Length unit is incorrect. C) One extra factor of $\mathbf{s}^{\mathbf{- 1}}$ has been included. D) Energy has no time dependence. Reasoning: $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 3}}$ is the unit of power, not energy. Energy should be $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$. 31 / 32 Which pair has identical SI base units? A) Energy and Power B) Momentum and Force C) Density and Pressure D) Pressure and Stress Reasoning: Both pressure and stress are force per unit area. 32 / 32 The unit $\mathbf{kg\ m}\mathbf{s}^{\mathbf{- 2\ }}\mathbf{m}^{\mathbf{- 2}}$ simplifies to: A) $\mathbf{kg\ }\mathbf{m}^{\mathbf{2\ }}\mathbf{s}^{\mathbf{- 2}}$ B) $\mathbf{kg\ m\ }\mathbf{s}^{\mathbf{- 1}}$ C) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$ D) $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 2\ }}\mathbf{s}^{\mathbf{- 2}}$ Reasoning: $\mathbf{m \times}\mathbf{m}^{\mathbf{- 2}}\mathbf{=}\mathbf{m}^{\mathbf{- 1}}$, giving $\mathbf{kg\ }\mathbf{m}^{\mathbf{- 1\ }}\mathbf{s}^{\mathbf{- 2}}$. Your score is 0% Restart quiz
