For a body travelling with uniform acceleration its final velocity is v=180−9x where x is the distance travelled by the body then the acceleration is

given final velocity =v=180−9xsquaring both sides⇒v2=180−9x Compare this equation with v2=u2+2asv2=u2+2assince x =s=displacement∴−9=2a⇒a=−4.5m/s2⇒a=−4.5m/s2=acceleration