How do Newton's three laws of motion explain the movement of people and objects around you?

Newtons first law-An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force

Newtons second law-The acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object

Newtons third law-For every action, there is an equal and opposite reaction

Explanation:

1- Imagine a ball rolling down the hill,it will be moving down unless something stops it.  and the ball stops, unless you or an unbalanced force acts it will be at  rest

2-If you use the same force to push a truck and push a car, the car will have more acceleration than the truck, because the car has less mass.  It is easier to push an empty shopping cart than a full one, because the full shopping cart has more mass than the empty one.

3-If I kick my friend he will also kick me back. Better example-when you jump, your legs apply a force to the ground, and the ground applies and equal and opposite reaction force that propels you into the air. Engineers apply Newton's third law when designing rockets and other projectile devices.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.