Question

As a fish jumps vertically out of the water, assume that only two significant forces act on it: an upward force F exerted by the tail fin and the downward force due to gravity. A record Chinook salmon has a length of 1.50 m and a mass of 49.5 kg. If this fish is moving upward at 3.00 m/s as its head first breaks the surface and has an upward speed of 5.60 m/s after two-thirds of its length has left the surface, assume constant acceleration and determine the following.
(a) the salmon's acceleration?
(b) the magnitude of the force F during this interval?

Answer 1

I know for the second part i have to do F(Total) = m( a + g). But i don't know how to solve for the accelaration

Answer 2

the average speed over the interval is (3.00 m/s + 5.60 m/s) / 2 = 4.30 m/s

2/3 of its length is 1.00 m

so the time of the interval is
... 1.00 m / 4.30 m/s

the change in speed is
... 5.30 m/s - 3.00 m/s

acceleration is ... speed change / time

Answer 3

Okay so I solved for it then plugged my answer (11.3) into the second equation and got 1044. Thank you!