Answer:
The first option is the best
Answer:
In 2.748 sec the mailbag reached the ground
Explanation:
We have given height from the ground 
At t =2.25 sec helicopter releases a small mailbag so at t = 2.25 sec height from the ground 
When the mail box is drooped its initial velocity would zero so u = 0 m/sec
Acceleration due to gravity 
According to third law of motion 
t = 2.748 sec
Answer:
A kid becoming an adult
A leg becoming bruised
A person's blood pressure raising because they are running
need a picture to answer specific questions.
Explanation:
All of these are physical changes. Hope that this helps you and have a great day :)
Answer:
When she stretches her arms out,<em> B) her angular speed ω increases due to her moment of inertia decreasing</em>
Explanation:
The angular momentum of a rotating object is defined as the product of its moment of inertia and angular speed.
<em>L = I ω</em>
<em>where</em>
- <em>L is the angular momentum</em>
- <em>I is the moment of inertia</em>
- <em>ω is the angular speed</em>
<em />
According to the principle of conservation of angular momentum, if there is no external torque, angular momentum of the skater must remain conserved. If the initial and final moment of inertia is <em>I_i and I_f </em>while corresponding angular velocities are <em>ω_i and ω_f , </em>then the principle of conservation of angular momentum can be expressed as the following equation:
<em>(I_f) (ω_f) = (I_i) (ω_i)</em>
<em>ω_f / ω_i = I_i / I_f</em>
<em />
From the expression above, we can see that if the moment of inertia decreases, angular velocity would increase to conserve angular momentum of the skater.
Therefore, When she stretches her arms out,<em> her angular speed ω increases due to her moment of inertia decreasing.</em>
