An object falls from a high altitude and falls to the ground after 3 seconds. It is known that the falling distance in the first second is 5.4m, and the falling distance in each second after that is 9.8m more than the previous 1 second. How many meters is the object from the ground before falling?
一个物体从高空下落，经过3秒落地，已知第一秒下落距离是5.4m，以后每秒下落距离都比之前1秒多9.8m，这个物体下落前距地面多少米？
<gadget id="calculator">5.4 * 3</gadget>
<output>16.2</output>

<gadget id="calculator">9.8 * 3</gadget>
<output>29.4</output>

<gadget id="calculator">16.2 + 29.4</gadget>
<output>45.6</output>

<result>45.6</result>