Unit conversions Transitional Reasoning Practice

Questions

1. 1.

   In a high-energy physics experiment, a particle detector records an energy release of $3.2 \times 10^8\text{ erg}$ during a collision event. In the CGS system, the erg is defined as $1\text{ g}\cdot\text{cm}^2/\text{s}^2$, while the coherent SI unit of energy is the joule, defined as $1\text{ kg}\cdot\text{m}^2/\text{s}^2$. What is this energy release expressed in joules?

   • A) 32 J
   • B) 3200 J
   • C) 3.2 J
   • D) 0.32 J
2. 2.

   An automotive engineer tests the emergency braking system of a prototype electric car and records a deceleration of 7.2 km/(h·s). To evaluate the vehicle's stopping performance using equations calibrated in coherent SI base units, this rate must be expressed in meters per second squared (m/s$^2$). What is the magnitude of this deceleration in m/s$^2$?

   • A) 0.20 m/s$^2$
   • B) 2.0 m/s$^2$
   • C) 7.2 m/s$^2$
   • D) 26 m/s$^2$
3. 3.

   During a materials science experiment, an ultraviolet laser delivers an energy dose of 45 mJ/cm$^2$ to a polymer surface. To analyze the thermal degradation using equations calibrated in coherent SI units, this dose must be expressed in joules per square meter (J/m$^2$). What is this value in J/m$^2$?

   • A) 0.45 J/m$^2$
   • B) 4.5 J/m$^2$
   • C) 45 J/m$^2$
   • D) 450 J/m$^2$
4. 4.

   An environmental scientist records the rate of solar radiation absorbed by a test surface as 4.5 kJ/(m²·min). To integrate this measurement into a thermodynamic simulation configured for coherent SI units, the value must be converted to watts per square meter (W/m², where 1 W = 1 J/s). What is this rate expressed in W/m²?

   • A) 0.075 W/m²
   • B) 4.5 W/m²
   • C) 270,000 W/m²
   • D) 75 W/m²
5. 5.

   An electronics technician tests a compact rechargeable cell used in a wireless environmental sensor and measures its full charge capacity as 720 mA·h. To model the circuit's discharge dynamics in standard SI units where electric charge is measured in coulombs (1 C = 1 A·s), this rating must be converted to coulombs. What is the cell's charge capacity expressed in coulombs?

   • A) 43.2 C
   • B) 2592 C
   • C) 43,200 C
   • D) 2,592,000 C
6. 6.

   During a biomedical acoustics trial, an ultrasound pulse travels through a synthetic tissue phantom at a speed of 1.5 mm/μs. To analyze the wave propagation using standard simulation software configured for coherent SI base units, this speed must be converted to meters per second (m/s). What is this speed expressed in m/s?

   • A) 1500 m/s
   • B) 1.5 m/s
   • C) 0.0015 m/s
   • D) 15 000 m/s
7. 7.

   A student measures the mass of a metal block as 810 g and determines its volume to be 300 cm$^3$. To compare this result with standard reference tables recorded in SI base units, the student needs to express the density in kilograms per cubic meter. What is the density of the metal block in $\text{kg/m}^3$?

   • A) $2.7\text{ kg/m}^3$
   • B) $2700\text{ kg/m}^3$
   • C) $270\text{ kg/m}^3$
   • D) $0.0027\text{ kg/m}^3$

Answers and step-by-step solutions appear after you finish the test.