Question

A fish is able to jump vertically out of the water with a speed of 5.6 m/s. How much time in seconds does it take for the fish to pass a point 0.4 m above the water on the way up?

Answer 1

velocity of the fish when it is just out of the water, u = 5.6 m/s

acceleration due to gravity, g = -9.81 m/s² [ the negative sign indicates that acceleration due to gravity is acting downward].

time taken by the fish = t seconds

height , h = 0.4 m

we know,

Solution : t = 1.065 s, 0.0766s

The larger value of t is the one when the fish attains 0.4m on its way back to the water.

So, the acceptable solution is t =0.0766s

The fish takes 0.0766s to pass a point 0.4m above the water on the way up (ans)