Answer:
Electromagnetic waves do not require a medium in order to transport their energy. Mechanical waves are waves that require a medium in order to transport their energy from one location to another. ... Sound is a mechanical wave and cannot travel through a vacuum.
Answer:
9.8 m/s/s
Explanation:
The numerical value, in meters per second squared, of the acceleration of an object experiencing true free fall is 9.8 m/s/s. This is called the acceleration due to gravity.
Answer:
F = 147,78*10⁻⁹ [N]
Explanation:
By symmetry the Fy components of the forces acting on charge in point x = 0,7 m canceled each other, and the total force will be twice Fx ( Fx is x axis component of one of the forces .
The angle β ( angle between the line running through one of the charges in y axis and the charge in x axis) is
tan β = 0,5/0,7
tan β = 0,7142 then β = arctan 0,7142 ⇒ β = 35 ⁰
cos β = 0,81
d = √ (0,5)² + (0,7)² d1stance between charges
d = √0,25 + 0,49
d = √0,74 m
d = 0,86 m
Now Foce between two charges is:
F = K* q₁*q₂/ d² (1)
Where K = 9*10⁹ N*m²/C²
q₁ = 2,5* 10⁻⁹C
q₂ = 3,0*10⁻⁹C
d² = 0,74 m²
Plugging these values in (1)
F = 9*10⁹* 2,5* 10⁻⁹*3,0*10⁻⁹ / 0,74 [N*m²/C²]*C*C/m²
F = 91,21 * 10⁻⁹ [N]
And Fx = F*cos β
Fx = 91,21 * 10⁻⁹ *0,81
Fx =73,89*10⁻⁹ [N]
Then total force acting on charge located at x = 0,7 m is:
F = 2* Fx
F = 2*73,89*10⁻⁹ [N]
F = 147,78*10⁻⁹ [N]
Answer:
W = 882.9[J]
Explanation:
In order to be able to calculate the work, we must first calculate the force necessary to lift the box. Since the necessary force is equivalent to the weight of the box, we can determine the weight of the box by means of the product of mass by gravitational acceleration.

where:
w = weight [N]
m = mass = 30 [kg]
g = gravity acceleration = 9.81 [m/s²]
![w = 30*9.81\\w = 294.3 [N]](https://tex.z-dn.net/?f=w%20%3D%2030%2A9.81%5C%5Cw%20%3D%20294.3%20%5BN%5D)
Now, the work can be calculated multiplying the force (weight) by the distance [m]
![W = w*d\\W = 294.3*3\\W=882.9[J]](https://tex.z-dn.net/?f=W%20%3D%20w%2Ad%5C%5CW%20%3D%20294.3%2A3%5C%5CW%3D882.9%5BJ%5D)