Question

A boat is traveling at 43.2km/hr. It then goes down a faster part of the river and is now going 144km/hr which gave the boat an acceleration of 25.2km/hr squared . How long did it take the boat to reach its new speed

Answer 1

Explanation:

with this we would use the first equation of motion.

`v = u + at`

making t the subject of the equation

`t = (v - u)/(a)`

where v is 144 km/h and u 43.2 km per hour and a is 25.2 kilometres per square hour.

`t = (144 - 43.2)/(25.2)`

`t = 4 \: hr`

therefore the time taken for the boat to reach its new speed is 4 hours.

Answer 2

43.2 + 25.2h = 144

25.2h = 100.8

h = 4 hours