Answer:
Muscles work in pairs to move a bone.
Skeletal muscles only PULL in one direction. For this reason they always come in pairs. When one muscle in a pair contracts, to bend a joint for example, its counterpart then contracts and pulls in the opposite direction to straighten the joint out again.
Answer:
positive force → balanced force → negative force
Explanation:
np
Answer:1:En química, el número másico o número de masa es la suma del número de protones y el número de neutrones del núcleo de un átomo. Se simboliza con la letra A (el uso de esta letra proviene de alemán Atomgewicht, que quiere decir peso atómico, aunque sean conceptos distintos que no deben confundirse).
2:
Answer:
The book sitting on the desk
Explanation:
The gravitational potential energy of an object is the energy possessed by the object due to its position relative to the ground.
It is calculated as:
where
m is the mass of the object
g is the acceleration due to gravity
h is the height of the object with respect to the ground
From the formula, we see that the GPE of an object is directly proportional to the heigth h: so, the higher the location of the object, the larger the GPE.
In this problem, we are comparing a book sitting on a desk and the same book sitting on the floor. In the two situations, the mass of the book is the same; however, in the first case, the value of the height is h, while in the second case, the value of h is lower (because the book is located at a lower height, being on the floor).
Therefore, we can conclude that the first book must have a larger GPE, since it has a larger value of h.
The answer is: A) Na3PO4 + 3KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction.
This chemical reaction is double displacement reaction - cations (K⁺ and Na⁺) and anions (PO₄³⁻⁻ and OH⁻) of the two reactants switch places and form two new compounds.
Na₃PO₄ is sodium phosphate.
KOH is potassium hydroxide.
NaOH is sodium hydroxide.
K₃PO₄ is potassium phosphate.
According to the mass conservation law, there are same number of atoms on both side of balanced chemical reaction.
