Answer:
a. Temperatures increase can change a solid to a liquid, but cannot change a liquid to a solid
b. The particles in a solid are much closer together than the particles in a liquid.
Explanation:
Any material expands when heated and contracts when cooled. So, when a body is heated to a particular temperature, it starts melting and changes into a liquid.
As the material expands the distance between the atoms or molecules increases and it will become a liquid. So it can move around the material. It doesn't become solid on further heating. But water is an exception where it contracts when heated from 0° to 4° C.
In solids, these atoms or molecules are closely packed. It is rigidly fixed.
The solid, as well as the liquid, has a definite volume, but the liquid does not have a definite shape.
<span>The protons and neutrons are much more massive than the electrons.
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The electrons are simply too small to really change the mass, so they aren't counted.
Answer:
V = x/t
where:
x = distance [m]
t = time [s]
V = velocity [m/s]
Explanation:
Speed is defined as the distance travelled by a body in a given time interval. The velocity or speed is a vector, that is, it has magnitude and direction.
By virtue of its vector character, the direction of the displacement and the module, which is called speed, must be considered to define the velocity.
<u>Average speed</u>
The average speed is defined as the change of position over a given time interval. It is calculated by dividing the displacement vector (Δx) between the time interval (Δt) used.
<u>Instant speed</u>
Instantaneous velocity is a vector tangent to the trajectory, corresponding to the derivative of the vector position relative to time.
It allows to know the speed of a mobile that moves on a trajectory when the interval of time is infinitely small, being then the space traveled also very small, representing a point of the trajectory. Instant velocity is always tangent to the trajectory.
An electric motor converts electrical energy into physical movement. Electric motors generate magnetic fields with electric current through a coil. The magnetic field then causes a force with a magnet that causes movement or spinning that runs the motor.
Answer:
1.84 m from the initial point (3.16 m from the ceiling)
Explanation:
According to the law of conservation of energy, the initial kinetic energy of the ball will be converted into gravitational potential energy at the point of maximum height.
Therefore, we can write:
where
m = 2 kg is the mass of the ball
v = 6 m/s is the initial speed of the ball
g = 9.8 m/s^2 is the acceleration due to gravity
is the change in height of the ball
Solving for ,
So, the ball raises 1.84 compared to its initial height.
Therefore:
- if we take the initial position of the ball as reference point, its maximum height is at 1.84 m
- if we take the ceiling as reference point, the maximum height of the ball will be
5 m - 1.84 m = 3.16 m from the ceiling
