Đáp án:

\(\begin{array}{l}
33.D.0,185m/{s^2};333m\\
34.D.t = 100s\\
35.B.a = 0.1m/{s^2};v = 18m/s\\
36.B.0,1m/{s^2}\\
37.D.21m\\
38.A.s = 45m\\
39.C. - 1m/{s^2};50m\\
40.A.a =  - 0,5m/{s^2}\\
41.C.4s\\
42.C.26/s\\
43.B.v = 4(t - 1)(m/s)\\
44.A. - 0,8m/{s^2}\\
45.B.{v_0} =  - 4m/s\\
46.B
\end{array}\)

Giải thích các bước giải:

\(\begin{array}{l}
33.D.0,185m/{s^2};333m\\
v = 40km/h = \dfrac{{100}}{9}m/s\\
t = 1p = 60s\\
a = \dfrac{{v - {v_0}}}{t} = \dfrac{{\dfrac{{100}}{9} - 0}}{{60}} = 0,185m/{s^2}\\
s = \dfrac{1}{2}a{t^2} = \dfrac{1}{2}.0,{185.60^2} = 333m\\
34.D.t = 100s\\
v = 36km/h = 10m/s\\
a = \dfrac{{v - {v_0}}}{t} \Rightarrow t = \dfrac{{v - {v_0}}}{a} = \dfrac{{10 - 0}}{{0,1}} = 100s\\
35.B.a = 0.1m/{s^2};v = 18m/s\\
a = \dfrac{{v - {v_0}}}{t} = \dfrac{{14 - 10}}{{20}} = 0,2m/{s^2}\\
v = {v_0} + at = 10 + 0,2.40 = 18m/s\\
36.B.0,1m/{s^2}\\
{v_0} = 36km/h = 10m/s\\
v = 54km/h = 15m/s\\
a = \dfrac{{{v^2} - v_0^2}}{{2s}} = \dfrac{{{{15}^2} - {{10}^2}}}{{2.625}} = 0,1m/{s^2}\\
37.D.21m\\
s = {v_0}t + \dfrac{1}{2}a{t^2} = 10.3 + \dfrac{1}{2}.( - 2){.3^2} = 21m\\
38.A.s = 45m\\
{v_0} = 54km/h = 15m/s\\
a = \dfrac{{v - {v_0}}}{t} = \dfrac{{0 - 15}}{6} =  - 2,5m/{s^2}\\
s = {v_0}t + \dfrac{1}{2}a{t^2} = 15.6 + \dfrac{1}{2}.( - 2,5){.6^2} = 45m\\
39.C. - 1m/{s^2};50m\\
{v_0} = 36km/h = 10m/s\\
a = \dfrac{{v - {v_0}}}{t} = \dfrac{{0 - 10}}{{10}} =  - 1m/{s^2}\\
s = {v_0}t - \dfrac{1}{2}a{t^2} = 10.10 + \dfrac{1}{2}.( - 1){.10^2} = 50m\\
40.A.a =  - 0,5m/{s^2}\\
a = \dfrac{{{v^2} - v_0^2}}{{2s}} = \dfrac{{0 - {{10}^2}}}{{2.100}} =  - 0,5m/{s^2}\\
41.C.4s\\
{v_0} = 36km/h = 10m/s\\
a = \dfrac{{{v^2} - v_0^2}}{{2s}} = \dfrac{{0 - {{10}^2}}}{{2.20}} =  - 2,5m/{s^2}\\
a = \dfrac{{v - {v_0}}}{t} \Rightarrow t = \dfrac{{v - {v_0}}}{a} = \dfrac{{0 - 10}}{{ - 2,5}} = 4s\\
42.C.26/s\\
x = {v_0}t + \dfrac{1}{2}a{t^2} = 10t + 4{t^2}\\
 \Rightarrow \left\{ \begin{array}{l}
{v_0} = 10m/s\\
a = 8m/{s^2}
\end{array} \right.\\
v = {v_0} + at = 10 + 8.2 = 26m/s\\
43.B.v = 4(t - 1)(m/s)\\
x = {x_0} + {v_0}t + \dfrac{1}{2}a{t^2} = 3 - 4t + 2{t^2}\\
 \Rightarrow \left\{ \begin{array}{l}
{x_0} = 3m\\
{v_0} =  - 4m/s\\
a = 4m/{s^2}
\end{array} \right.\\
v = {v_0} + at =  - 4 + 4t = 4(t - 1)(m/s)\\
44.A. - 0,8m/{s^2}\\
x = {v_0}t + \dfrac{1}{2}a{t^2} = 10t - 0,4{t^2}\\
 \Rightarrow \left\{ \begin{array}{l}
{v_0} = 10m/s\\
a =  - 0,8m/{s^2}
\end{array} \right.\\
45.B.{v_0} =  - 4m/s\\
x = {x_0} + {v_0}t + \dfrac{1}{2}a{t^2} = 3 - 4t + 2{t^2}\\
 \Rightarrow \left\{ \begin{array}{l}
{x_0} = 3m\\
{v_0} =  - 4m/s\\
a = 4m/{s^2}
\end{array} \right.\\
46.C\\
x = {x_0} + {v_0}t + \dfrac{1}{2}a{t^2} = {t^2} - 4t + 10\\
 \Rightarrow \left\{ \begin{array}{l}
{x_0} = 10m\\
{v_0} =  - 4m/s\\
a = 2m/{s^2}
\end{array} \right.
\end{array}\)

Vì a>0 nên xe chuyển động nhanh dần đều

47.

Xe chuyển động nhanh dần đều từ 0-20s

Xe chuyển động thẳng đều từ 20-60s

Xe chuyển động chậm dần đều từ 60-70s