Given :
A boat is travelling 5 m/s and accelerates at a rate of 3 m/s² .
u = 5 m/s.
a = 3 m/s².
To Find :
How long will it take for the boat to reach a velocity of 20 m/s.
Solution :
Final velocity is v =20 m/s.
By equation of motion :
![v=u+at](https://img.qammunity.org/2021/formulas/physics/college/vv2rsqtmhe6xfaudlnnjs5d8rddar7pn56.png)
Putting all given values :
![20 = 5 + 3t\\\\t = 5 \ s](https://img.qammunity.org/2021/formulas/mathematics/high-school/pp7nn66m15uudtk5felwtc20x5xzwzneb9.png)
Therefore, time taken to reach 20 m/s is 5 seconds.
Hence, this is the required solution.