Mastery Level Check Point
Level 3
3. Nurul had two similar sheets, Y and Z, made of the same material. She placed
the sheets on a heater as shown.
.
sheet Y
sheet Z
heater
At the start, sheets Y and Z were of the same length. After a while, sheet Z
became longer than sheet Y.
(a) Give a reason why sheet Z became longer than sheet Y. [1]

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?