Yes dams are made wider at the bottom because the pressure of the water pressure is greater there
        
             
        
        
        
The Two examples of contact forces are:
- frictional force 
- Contact force.
The two examples of non contact forces are:
- Gravitational force
- magnetic force.
Contact forces happens due to the contact between two objects
Non Contact forces happens because there is no contact between two objects. There is no attraction.
 
        
             
        
        
        
Answer:
Magnitude and direction. 
Explanation:
Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction. 
Mathematically, velocity is given by the equation;

Gravity is considered to be a universal force of attraction which acts between all objects that has both mass, energy and occupy space. Therefore, it acts in such a way as to bring objects together.
Additionally, the gravity of earth makes it possible for all physical objects to possess weight.
Hence, in free fall, the magnitude and direction of velocity of the object changes. 
 
        
             
        
        
        
Net force = (mass) x (acceleration)... that’s Newton’s 2nd law of motion. 
Net force = (15kg) x (10 m/s squared) 
Net force = 150 Newtons.