a second truck arrives whose ladder, when extended,is 30 meters long. the base of this ladder is also 4 metres above the ground. for safety reasons, the max angle of elevation that the ladder can make is 70%

Answer: The maximum height of the wall that can be reached by the ladder on the second truck = 58.19 meters
Step-by-step explanation:
A diagram for the given situation is attached.
To find: AC
In right triangle ABF,
[tex]\dfrac{AB}{AE}=\sin 70^{\circ}\\\\\Rightarrow\ \dfrac{AB}{30}=0.9397\\\\\Rightarrow\ AB=30\times0.9397\approx 28.19[/tex]
Now AC = AB + BC = 28.19 + 30 meters = 58.19 meters
Therefore, the maximum height of the wall that can be reached by the ladder on the second truck = 58.19 meters