Answer:
(A) 9.5 m/s
(B) 5.225 m
Explanation:
vertical height (h) = 4.7 m
horizontal distance (d) = 9.3 m
acceleration due to gravity (g) = 9.8 m/s^{2}
initial speed of the fish (u) = 0 m/s
(A) what is the pelicans initial speed ?
s = ut +
since u = 0
s =
t =
where a = acceleration due to gravity and s = vertical height
t = = 0.98 s
speed of the fish = distance / time = 9.3 / 0.98 = 9.5 m/s
initial speed of the pelican = 9.5 m/s
(B) If the pelican was traveling at the same speed but was only 1.5 m above the water, how far would the fish travel horizontally before hitting the water below?
vertical height = 1.5 m
pelican's speed = 9.5 m/s
s = ut +
since u = 0
s =
t =
where a = acceleration due to gravity and s = vertical height
t = = 0.55 s
distance traveled by the fish = speed x time = 9.5 x 0.55 = 5.225 m
Answer:
θ = 12.95º
Explanation:
For this exercise it is best to separate the process into two parts, one where they collide and another where the system moves altar the maximum height
Let's start by finding the speed of the bar plus clay ball system, using amount of momentum
The mass of the bar (M = 0.080 kg) and the mass of the clay ball (m = 0.015 kg) with speed (v₀ = 2.0 m / s)
Initial before the crash
p₀ = m v₀
Final after the crash before starting the movement
= (m + M) v
p₀ =
m v₀ = (m + M) v
v = v₀ m / (m + M)
v = 2.0 0.015 / (0.015 +0.080)
v = 0.316 m / s
With this speed the clay plus bar system comes out, let's use the concept of conservation of mechanical energy
Lower
Em₀ = K = ½ (m + M) v²
Higher
= U = (m + M) g y
Em₀ =
½ (m + M) v² = (m + M) g y
y = ½ v² / g
y = ½ 0.316² / 9.8
y = 0.00509 m
Let's look for the angle the height from the pivot point is
L = 0.40 / 2 = 0.20 cm
The distance that went up is
y = L - L cos θ
cos θ = (L-y) / L
θ = cos⁻¹ (L-y) / L
θ = cos⁻¹-1 ((0.20 - 0.00509) /0.20)
θ = 12.95º