A steel rod is initially at \( 20^\circ\mathrm{C} \) and has a length of \( 2\,\mathrm{m} \). It has a cross-sectional area of \( 0.001\,\mathrm{m^2} \) If it is heated to \( 120^\circ\mathrm{C} \), how large a force must be applied to its end to restore the original length? Use \( 12\times10^{-6}\mathrm{(C^\circ)^{- 1}} \).​

Which of the following are properties of mechanical waves? check all that apply ⭕️ particles of the medium move back and fourth, but do not move with the wave. ⭕️ the particles of the medium always move parallel to the wave motion. ⭕️ wave motion begins with a disturbance in the medium. ⭕️ waves transport energy from a source outward, away from the source.

Which of the following is not a part of the respiratory system? a. pharynx b. trachea c. pancreas d. larynx hurrim timed

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?