Which of these describes an endothermic process? (2 points) When lithium is placed in water, the temperature of the container in
2 answers:
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Answer:
11.2m
Explanation:
Suppose the pumpkin is launched vertically and the speed of 13.9 m/s is absolutely vertical. As the pumpkin rises up, its kinetic energy is converted to potential energy, let the reference point be the round, we can create the following equation from the law of energy conservation:
we can substitute
We can also divide both sides by m and 0.5
Answer:
The height above the waterline that the stream reaches at the horizontal position of the insect is 15 cm.
Explanation:
Please, see the attached figure for a description of the problem.
The motion is parabolic and this is the equation that describes the position of an object in such a motion:
r = (x0 + v0 · t · cos α, y0 + v0 · t · sin α + 1/2 · g · t²)
Where:
r = position vector
x0 = initial horizontal position
v0 = initial velocity
t = time
α = angle of the stream with the waterline
y0 = initial vertical position
g = acceleration due to gravity
First, let´s calculate how much time it takes the stream to reach the horizontal position of 0.27 m. For this, we will use the equation of the x-component of the vector position:
x = x0 + v0 · t · cos α
Since the origin of the reference system is located at the mouth of the fish, x0 = 0. Then:
0.27 m = 3.7 m/s · t · cos 35º
t = 0.27 m /(3.7 m/s · cos 35º)
t = 0.089 s
Now, with this time, we can calulate the vertical position (height) of the stream using the equation for the y-component of the vector "r":
y = y0 + v0 · t · sin α + 1/2 · g · t²
y = 0 m + 3.7 m/s · 0.089 s · sin 35º + 1/2 · (-9.8 m/s²) · (0.089s)²
y = 0.15 m
when the stream reaches 27 cm horizontally, it will reach 15 cm vertically and hit the insect!
