Answer:
Respuesta correcta, opción D: Es la fuerza que un cuerpo ejerce perpendicularmente sobre el área en la que actúa.
Explanation:
La definición de presión es la fuerza que un cuerpo ejerce en dirección perpendicular sobre el área en la que actúa.
Cuando se aplica una fuerza sobre la superficie de un cuerpo, la presión es la siguiente:

En donde:
F es la fuerza aplicada.
A es el área del cuerpo.
Por lo tanto la opción correcta es la D: es la fuerza que un cuerpo ejerce perpendicularmente sobre el área en la que actúa.
Espero que se sea de utilidad!
<h2>
Answer:</h2>
The rate of deceleration is -0.14
<h2>
Explanation:</h2>
Using one of the equations of motion;
v = u + at
where;
v = final velocity of the boat = 0m/s (since the boat decelerates to a stop)
u = initial velocity of the boat = 25m/s
a = acceleration of the boat
t = time taken for the boat to accelerate/decelerate from u to v = 3 minutes
<em>Convert the time t = 3 minutes to seconds;</em>
=> 3 minutes = 3 x 60 seconds = 180seconds.
<em>Substitute the values of v, u, t into the equation above. We have;</em>
v = u + at
=> 0 = 25 + a(180)
=> 0 = 25 + 180a
<em>Make a the subject of the formula;</em>
=> 180a = 0 - 25
=> 180a = -25
=> a = -25/180
=> a = -0.14
The negative value of a shows that the boat is decelerating.
Therefore, the rate of deceleration of the speed boat is 0.14
Answer:
1. a
2. b
3. b
Explanation:
1.
Resistance is the property of a conductor to offer resistance to the flow of current. The lower the resistance better is the conductivity of wire.
We know that the resistance of a wire depends on several factor which are inter-connected by an equation as:
where:
R = resistance of the wire
length of the wire
cross sectional area of the wire
from the above relation we observe that

- Also when the temperature of the wire is significantly high then the lattice vibration cause obstruction in the path of the flowing charges and reduce the current flow.
2.
As the collision between the electrons and protons increases the speed of the flow of charges will decrease because the opposite charges attract each other and as we know that electrical current is the rate of flow of charge.
3.
Heating up of wire due to sunlight will cause lattice vibration in the conductor and will obstruct the movement of the charges which build up electric current, hence increasing the resistance of conductivity.
Magnetism is the force exerted by magnets when they attract or repel each other. Magnetism is caused by the motion of electric charges. Every substance is made up of tiny units called atoms. Each atom has electrons, particles that carry electric charges.
Answer:
<h2>Changes</h2>
Explanation:
<h3>Variable is something that varies and doesn't remain constant.</h3>