A pelican flying along a horizontal path drops a fish from a height of 5.4m. The fish travels 8.0 m horizontally before it hits the water below. What was the pelican's speed?
The pelican was going 7.6 m/s
A pelican flying along a horizontal path drops
a fish from a height of 5.4 m. The fish travels
8.9 m horizontally before it hits the water
below.
What was the pelican’s initial speed? The
acceleration of gravity is 9.81 m/s
2
.
Answer in units of m/s.
To find the pelican's speed, we can use the equations of motion. In this case, the horizontal distance traveled by the fish (8.0m) is equal to the product of the pelican's speed and the time it takes for the fish to fall.
First, let's find the time it takes for the fish to fall. We can use the equation:
h = 0.5 * g * t^2
where:
h is the height (5.4m),
g is the acceleration due to gravity (approximately 9.8m/s^2),
t is the time.
Rearranging the equation to solve for t, we get:
t^2 = (2h) / g
Substituting the given values:
t^2 = (2 * 5.4m) / 9.8m/s^2
t^2 = 1.1s^2
Taking the square root of both sides:
t = 1.05s
Now, we can calculate the pelican's speed using the equation:
speed = distance / time
Substituting the given values:
speed = 8.0m / 1.05s
speed ≈ 7.62m/s
Therefore, the pelican's approximate speed is 7.62 m/s.
Calculate the time, t sec., it takes to free-fall from rest over 5.4 m.
You can use:
S=ut+(1/2)gt²
where S=distance, u=initial vertical speed=0, and g=acceleration due to gravity.
Divide 8 m/t sec. to get the horizontal speed.