Question

Answer 1

Quãng đường vật đi trong giây cuối cùng:

\(h=\dfrac{1}{2}gt^2-\dfrac{1}{2}g\left(t-1\right)^2\)

   \(=\dfrac{1}{2}\cdot10\cdot7^2-\dfrac{1}{2}\cdot10\cdot\left(7-1\right)^2=65m\)

Answer 2

\(\left\{{}\begin{matrix}s_{\left(7s\right)}=\dfrac{1}{2}gt^2=\dfrac{1}{2}\cdot10\cdot7^2=245\left(m\right)\\s_{\left(6s\right)}=\dfrac{1}{2}gt^2=\dfrac{1}{2}\cdot10\cdot6^2=180\left(m\right)\end{matrix}\right.\)

\(\Rightarrow\Delta s=s_{\left(7s\right)}-s_{\left(6s\right)}=245-180=65\left(m\right)\)