Given :
Initial velocity , u = 15 m/s .
Final velocity , v = 30 m/s .
Distance travelled , d = 40 m .
Also , this body is uniformly accelerating .
To Find :
(a) What is the acceleration .
(b) How long does this take .
Solution :
Let , acceleration be a .
By , equation of motion :
[tex]v^2-u^2=2ad\\\\a=\dfrac{v^2-u^2}{2d}\\\\a=\dfrac{30^2-15^2}{2\times 40}\\\\a=8.44\ m/s^2[/tex]
Also , by equation :
[tex]v=u+at\\\\t=\dfrac{v-u}{a}\\\\t=\dfrac{30-15}{8.44}\ s\\\\t=1.78\ s[/tex]
Hence , this is the required solution .
