Answer:
16.935 N
Explanation:
In order to make the box start moving, the level force applied on the box (F) must be greater than the force of static friction that keeps the box at rest, which is equal to

where
is the coefficient of static friction
(mg) = 30 N is the weight of the box
Therefore, the condition for F must be:

So, the applied force must be greater than this value.
<u>Answer</u>:
Effort is the unaltered force. Load is the altered force.
Answer:
500000N/m²
5250N
Explanation:
Given parameters:
Depth(H) = 50m
Density of water = 1000kg/m³
Acceleration of free fall = 10m/s
Unknown:
Pressure the water exerts on the diver = ?
Solution:
Pressure is the force per unit area on a body. In fluids, pressure is the product of density, gravity and height
Pressure in fluids = Density x acceleration due to gravity x height
Input the variables and solve;
Pressure in fluids = 1000 x 10 x 50 = 500000N/m²
B.
width of window = 150mm
height of window = 70mm
Force water exerts on the window = ?
To solve this problem;
Pressure = 
Area of the window = width x height = 150 x 10⁻³ x 70 x 10⁻³
= 1.05 x 10 ⁻²m²
Force = pressure x area
Input the variables;
= 500000N/m² x 1.05 x 10 ⁻²m²
= 5250N
A very small source of light that radiates uniformly in all directions produces an electric field with an amplitude of ܧ at a distance R from the source. What is the amplitude of the magnetic field at a point 2R from the source?
If the distance from the source is doubled. The amplitude of the magnetic field is smaller 4 times.