Answer:
No, not necessarily
Explanation:
If an object is moving with an acceleration that causes its speed to be reduced, there will be a moment in which it reaches v = 0, but this doesn't necessarily mean that the acceleration isn't acting anymore. If the object continues its movement with the same acceleration, it's velocity will become negative.
An example of an object that has zero velocity but non-zero acceleration:
If you throw an object in the air with a certain velocity, it will move vertically, reducing its velocity in a 9,8 
rate (which is the acceleration caused by gravity). At a certain point, the object will reach its maximum height, and will start to fall. In the exact moment that it reaches the maximum height, before it starts falling, its velocity is zero, but gravity is still acting on the object (this is the reason why it starts falling instead of just being stopped at that point). Therefore, at that point, the object has zero velocity but an acceleration of 9,8 .
<h3>Answer;</h3>
-Temperature
<h3><u>Explanation;</u></h3>
- Sound is a type of mechanical wave, which means it requires a material medium for transmission. It results from the vibration of particles.
- The speed of sound in mediums varies depending on the property of the medium and a number of other factors which includes; temperature, pressure, and humidity.
- Temperature increases the speed of sound wave as particles at higher temperatures tend to possess more energy and thus they will vibrate faster and thus the sound wave will travel faster.
Answer:
Friction is a surface force that opposes relative motion.
Answer:
Explanation:
The intensity of an electromagnetic wave can be expressed in terms of the magnetic field using the next relationship:
(1)
- c is the speed of light (3*10⁸ m/s)
- μ₀ is the permeability of free space (in vacuum ) (1.26*10⁻⁶ N/A²)
- B₀ is the magnetic field
Now, let's define the relationship between power (P) and average intensity (I).
- P is the power
- A is the area crossed
So we can calculate the power.
Finally, energy is the product of P times time, so:
I hope it helps you!
We can solve the problem by applying Newton's second law, which states that the resultant of the forces acting on an object is equal to the product between its mass and its acceleration:
We should consider two different directions: the direction perpendicular to the inclined plane and the direction parallel to it. Let's write the equations of the forces along the two directions, decomposing the weight of the object (mg):
(parallel direction) (1)
(perpendicular direction) (2)
where
is the angle of the inclined plane, N is the normal reaction of the plane,
is the frictional force, with
being the coefficient of friction.
From eq.(2), we find
and if we substitute into eq.(1), we can find the acceleration of the block:
from which
