Answer:
4. 10.0 m/s²
Explanation:
I) if initial velocity is 'v₀', the final velocity is 'v', the accelaration is 'a', the distance is 'L' and elapsed time if 't', then:
[tex]1. \ a=\frac{v-v_0}{t};[/tex]
[tex]2. \ L=\frac{at^2}{2}.[/tex]
II) using these two equations after substitution v₀=0; v=30 and L=45:
[tex]\left \{{{45 =\frac{at^2}{2}} \atop {a=\frac{30-0}{t} }} \right.[/tex]
[tex]\left \{ {{at^2=90} \atop {at=30}} \right. \ <=> \ \left \{ {{a=10} \atop {t=3}} \right.[/tex] [tex]=> \ a=10\frac{m}{s^2}[/tex]