\(\begin{array}{l}
a.{s_5} = 125m\\
b.s = 45m
\end{array}\)

Giải thích các bước giải:

a.

Quảng đường vật đi được trong 5s đầu tiên là:

\({s_5} = \dfrac{1}{2}g{t^2} = \dfrac{1}{2}{.10.5^2} = 125m\)

b.

Quảng đường vật đi được sau 4s là:

\({s_4} = \dfrac{1}{2}g{t^2} = \dfrac{1}{2}{.10.4^2} = 80m\)

Quảng đường vật đi được trong giây thứ 5 là:

\(s = {s_5} - {s_4} = 125 - 80 = 45m\)

Hey guys,whats up.My name Quoc.Im 15 years old.Today,I warna tell your about activites.In the morning,I often get up at 6.30a.m.I brush my teeth,wash the face and the I have breakfast.Monday at 7.30a.m I go to school.I finish my study at 11h30.I have lunch at 12h30.I have 1 hour to take a nap.At 13.30p.m,I go to school again.I finish all stuffe a 16h30.I come back hom at 17 o'clock I do somesports from 17h30 to 19h.After that I cook dinner with my farther and take a bath.I take 2 hours homework from 20h to 21h30.I go to bed at 21h45.That's all.Thank your for you're listening 

on school days I usually get up at 5:30. Then I clean myself with exercise. At 6 o'clock I change clothes, prepare books for class. I study from 7 am to 11:15 am. Afternoon from 1 pm to 5 pm. Go back to change clothes and play sports until 6:30 pm. After that, I eat lunch and study until 9:30 pm. Done and brush my teeth. then go to bed and start a new day