<h2>Answer::</h2>
A compass works by detecting and responding to the Earth's natural magnetic fields. The Earth has an iron core that is part liquid and part solid crystal, due to gravitational pressure. It is believed that movement in the liquid outer core is what produces the Earth's magnetic field.','.
explanation
a=average velocity/average time
average velocity=0.0+1.2+2.4+3.6/4
average velocity=7.2/4
average velocity=1.8 m/s
average time=0.0+3.0+6.0+9.0/4
average time=18/4
average time=4.5 s
a= average velocity/average time
a=1.8/4.5
a=0.4 m/s²
