Answer to Question #61850 in Physics for Blessed

Question

1 Which of the following is correct about the universe?
a. there is absolute rest but no absolute motion
b. there is absolute motion but no absolute rest
c. there is neither absolute rest nor absolute motion
d. everything is in motion at constant velocity

3. Which of the following physical quantities are dimensionally equivalent?
a. work and torque
b. velocity and acceleration
c. work and power
d. momentum and energy

Answer 1

1 Which of the following is correct about the universe?
a. there is absolute rest but no absolute motion
b. there is absolute motion but no absolute rest
c. there is neither absolute rest nor absolute motion
d. everything is in motion at constant velocity
Answer: c. there is neither absolute rest nor absolute motion.


3. Which of the following physical quantities are dimensionally equivalent?
a. work and torque
b. velocity and acceleration
c. work and power
d. momentum and energy
Answer: a. work and torque.

The SI unit for energy or work is the joule. It is dimensionally equivalent to a force of one newton acting over a distance of one meter, but it is not used for torque. Energy and torque are entirely different concepts, so the practice of using different unit names (i.e., reserving newton meters for torque and using only joules for energy) helps avoid mistakes and misunderstandings