Question

A bird is flying with a speed of 18.0 m/s over water when it accidentally drops a 2.00 kg fish. if the altitude of the bird is 5.40 m and friction is disregarded, what is thw speed of the fish when it hits the water?

Answer 1

In the given question there are several important information's provided and based on them the required answer can be easily deduced. Firstly the speed of the bird is 18.0 m/s. Then we also come to know that the weight of the fish is 2 kg.Altitude at which the bird is flying is 5.40 m. Also there are no frictional forces to be considered.Then:
Horizontal component (Vx) = 18 m/s
Vertical component (Vy) = sqrt(2 * g * h) where sqrt means square root.
Height (h) = 5.40 m
Gravity (g) = 9.8 m/s^2
Now we have to put all the known information's in the equations to deduce the actual solution.
Vy = sqrt (2 * 9.8 * 5.40) m/s
= sqrt ( 105.84) m/s
= 10.28 m/s
Now to find the speed of the fish when it hits water:
V = sqrt (Vx^2 + Vy^2)
= sqrt (324 + 105.84)
= sqrt(429.84)
= 20.73 m/s
So the velocity or speed of the fish when hitting the water is 20.73 m/s