Answer:
The options are not properly punctuated.
(a) cognitively impaired (b) using holophrases which is developmentally appropriate (c) language-delayed and needs professional assistance (d) trying to manipulate his father and needs to be disciplined
The correct answer is (b) using holophrases which is developmentally appropriate
Explanation:
Holophrases are one of the single-word utterances characteristic of children in the early stages of language acquisition, it is the use of a single word to express a complex idea. Holophrases are normal among toddlers within the age of two years below.
Hence the the use of "cup" by the toddler to express his intent for a cup of milk is referred to as holophrases which is developmentally appropriate
We want to study the impact of a sledgehammer and a wall.
Before the sledgehammer hits the wall, it has a given velocity and a given mass, so it has momentum and it has kinetic energy.
When it hits the wall, the velocity of the hammer disappears, this means that the energy is transferred to the wall, this "transfer of energy" can be thought of a force applied for a really short time on the wall, which for the third law of Newton, the force is also applied on the hammer.
This is why you feel the impact on the handle when you hit something with a hammer, this also means that some of the energy is dissipated on your arms.
Now, because the wall is made of a material usually not as strong as the head of the sledgehammer, we will see that in this interaction the wall seems more affected than the hammer, but the forces that each one experiences are exactly equal in magnitude.
If you want to learn more, you can read:
brainly.com/question/13952508
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Gravity is pushing you down on the earth while the friction from the ground is pushing you up. Those are the two frictions you must overcome when walking.
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Answer:

Explanation:
This is a projectile motion problem. We will first separate the motion into x- and y-components, apply the equations of kinematics separately, then we will combine them to find the initial velocity.
The initial velocity is in the x-direction, and there is no acceleration in the x-direction.
On the other hand, there no initial velocity in the y-component, so the arrow is basically in free-fall.
Applying the equations of kinematics in the x-direction gives

For the y-direction gives

Combining both equation yields the y_component of the final velocity

Since we know the angle between the x- and y-components of the final velocity, which is 180° - 2.8° = 177.2°, we can calculate the initial velocity.
