The ball is using an reaction and opposite reaction, so when you dribble a basketball you push the ball with downward force and the ground pushes the ball back up thus making the opposite reaction. 
        
             
        
        
        
Write the answer below the question?
        
             
        
        
        
Answer:

Explanation:
Net force by which man push the lawn mower is given as

now it is given that 37% of this force is vertically downwards
so we will have


now we also know that

here we have


Now work done by this force to move the lawn mower is given as



 
        
             
        
        
        
One of the equations of gravity is this:

Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up) 
h = height of object
Substitute for the values and you should have something like this



