Answer:
5.68 m/s
Explanation:
The motion of the salmon is the same as a projectile: it is launched with an initial speed at an angle of
above the horizontal.
The motion of the salmon consists of two indipendent motion:
- Along the horizontal direction, it is a uniform motion with constant velocity
So that the distance travelled is
(1)
- Along the vertical direction, it is a uniformly accelerated motion with constant acceleration downward, so the vertical displacement is
(2)
where g is the acceleration of gravity.
We know the following:
- The horizontal distance travelled by the salmon to reach the waterfall is
d = 2.33 m
- The vertical distance travelled is the height of the waterfall,
y = 0.488 m
From (1) we get:
And substituting into (2), we can solve the equation to find t, the time at which the salmon reaches the waterfall:
And then, we can use eq.(1) again to find the initial speed, u: