1. What are Forces?

2. Types of forces: To move an object you should to apply a force. For example: If you want to move a ball, what will you do? you will kick, throw it, or hit it with a bat. If you want to open a drawer, what will you do? you will pull it. If you want to move a chair, what will you do? you will push or pull it.

3. Force: any kind of pull or push Any object will keep moving until another force stop it. For example: when you catch a moving ball it will stop( because the force of your hand)

4. Friction is another type of force. Friction is any force that stop things or slow them down.(two objects rub together) Which one is easier pulling your bag on the street(smooth) or on the grass(rough)??? Why?

5. How can force affects the motion of an object? it can makes it start moving, stop moving, speed up, slow down, or change direction. magnetic force is an invisible force that push or pull metal object.

6. Forces change motion 1.The strength of the force.(ex: push the swing gently or hard) 1.The direction of the force.(ex: push a trolley to the right, it will moves to the right) 1.The mass of the object.( ex: throw or carry a pebble is easier than a rock )

7. Ahmad and Ali went to Dubai. Their car stop moving on the middle of the street. What will they do to move the car to the right side of the street to fix it?? both of them will push it Ahmad’s force + Ali’s force = net(total) force

8. Net force ** if two forces have the same direction(push car) net force= force 1+ force 2 ** if two forces have opposite directions net force= force 1 - force 2 If the two forces have the same strength they will cancel each other(net force is zero)