Answer:
1) 0 m/s²
2) 1.5 m/s²
3) 6.38 m/s²
4) -3.47 m/s²
Explanation:
The acceleration is given by:
[tex]a=\frac{vf-vo}{t}[/tex]
1)
For the first question, the acceleration is zero, because there is no change on its velocity:
[tex]a=\frac{(20m/s-20m/s)}{12}=0[/tex]
2)
[tex]a=\frac{(23.5m/s-12.1m/s)}{7.81}=1.5m/s^2[/tex]
3) here we have to make an conversion:
[tex]vo=0m/s\\vf=60.0\frac{mi}{h}*\frac{1m}{0.000621mi}*\frac{1h}{3600s}=26.8m/s[/tex]
[tex]a=\frac{(26.8m/s-0m/s)}{4.20}=6.38m/s^2[/tex]
4) here we have to use the following formula:
[tex]vf^2=vo^2+2*a*x\\\\a=\frac{vf^2-vo^2}{2*x}\\a=\frac{(18.9)^2-(33.4)^2}{2*(109)}=-3.47m/s^2[/tex]
