5. 31.5

square meters
5.【Solution】The surface area of the object is exactly equal to the surface area of a large cylinder plus the lateral surface areas of the medium and small cylinders. That is,
$$
\begin{aligned}
& 2 \times \pi \times 1.5^{2}+2 \times \pi \times 1.5 \times 1+2 \times \pi \times 1 \times 1+2 \times \pi \times 0.5 \times 1 \\
= & 4.5 \pi+3 \pi+2 \pi+\pi \\
= & 10.5 \pi \text { (square meters) }
\end{aligned}
$$

Taking the value of $\pi$ as 3, the above expression equals 31.5 (square meters)

Answer: The surface area of this object is 31.5 square meters
5. (As shown in the right figure) Three cylinders with heights of 1 meter and base radii of 1.5 meters, 1 meter, and 0.5 meters respectively are combined to form an object. Find the surface area of this object (take $\pi=3$).