The main reason why wheelchair ramps are used to move people up a staircase is because it has a high mechanical advantage which leads to a greater efficiency in moving people up the staircase.
- <em>Let the height of the staircase = h</em>
- <em>Let the length of the ramp = L</em>
The mechanical advantage of the ramp is calculated as follows;

As the length of the ramp increases, people will be move up to a greater distance up the staircase.
Thus, the main reason why wheelchair ramps are used to move people up a staircase is because it has a high mechanical advantage which leads to a greater efficiency in moving people up the staircase.
Learn more about mechanical advantages of ramps here: brainly.com/question/200179
Answer:
The following is the relation between electric force and field

Explanation:
Electric force is the magnitude of electrostatic forces between two charges which is directly proportional to product of both charges and inversely proportional to the square of the distance between them.

Here k is the coulumb's constant.
Where as the electric field is the electric force per unit charge. It is the function of electric force. It is the vector quantity and its direction is taken radially inward or outward depending on the nature of charge.
Its equation is
Electric Field 
Electric Field units are in volts where as Electric force units are newtons.
Answer:
B. Field
Explanation:
Gravity and Magnetism are defined as non-contact forces, so that eliminates option A.
Tension is found in a rope or a spring, and is a force in itself, so that eliminates option B.
A normal force is one that is perpendicular to the direction of a slope, so that eliminates option D.
Answer:
Tension in each cable is 3474 N when angle made by the string with horizontal 46 degree
Tension in each cable is 4852 N when angle made by the string with horizontal 31 degree
Explanation:
In this problem, for the boat to be at rest then tension in the strings must be such that the horizontal components balance each other and the vertical components balance weight of the boat.
Consider horizontal components for equilibrium
If the angle made by the string with horizontal 46 degree

Tension the each string is same
Consider vertical components for equilibrium

Tension in each cable is 3474 N when angle made by the string with horizontal 46 degree
If the angle made by the string with horizontal 31 degree, then

Tension in each cable is 4852 N when angle made by the string with horizontal 31 degree