Explanation:
Fluids exert both drag and lift forces on moving objects.  Drag is the frictional force opposing motion.  Lift is the force perpendicular to motion.
Some objects, like parachutes, are designed with large cross sectional areas to increase drag force.  Usually though, objects are designed to minimize drag force.  It's why cars, planes, and boats have sleek shapes.
Airplane wings have shapes called airfoils that generate lift.  It's what makes them fly.  The same shape is found in racecar spoilers.  These spoilers use lift force to push down on the rear tires, increasing traction.
 
        
             
        
        
        
Displacement is the final position of the object minus the initial position of the object. 
Xf - Xi. Displacement is not the distance of the object. If you go to the right 10m and to the left another 10m, your displacement is 0m. But your distance is 20m
        
             
        
        
        
The answer would be B, George Darwin :)
        
             
        
        
        
Answer:
When the object is placed at the focus the image is formed at infinity.
Explanation:
When a ray passes through focus and incident on a concave mirror then it will travel parallel to principal axis after reflection.Hence the image is formed at infinity.