Answer:
(a) 24.025 m/s. downward.
(b) 31 m
Explanation:
From Newton's equation of motion,
(a)
v = u + gt ................... Equation 1
Where v = final velocity, u = initial velocity, g = acceleration due to gravity, t = time.
Note: Let upward velocity be negative and downward be positive
Given: u = -0.5 m/s (upward), t = 2.5 s
Constant : g = 9.81 m/s²
Substitute into equation 1
v = 0.5+9.81(2.5)
v = -0.5+24.525
v = 24.025 m/s. downward.
(b) using
s₁ = ut + 1/2gt²......................... Equation 2
Where s₁ = distance at which the fish fall after being dropped by the pelican
Given: u = - 0.5 m/s, t = 2.5 s, g = 9.81 m/s²
Substitute into equation 2
s₁ = -0.5(2.5) + 1/2(9.81)(2.5)²
s₁ = -1.25+30.656
s₁ = 29.41 m
also,
s₂ = vt ................ Equation 3
Where s₂ = the distance by which the pelican rise during this time.
Given: v = 0.5 m/s, t= 2.5 s
s₂ = 0.5(2.5)
s₂ = 1.25 m.
Note: Distance between the pelican and fish = s₁ + s₂
Distance between the pelican and fish = 29.41+1.25
Distance between the pelican and fish = 30.66
Distance between the pelican and fish ≈ 31 m
