Forces

• Forces are measured using newtons (N)
• A force is anything that causes an object to change its speed, direction or shape
• A force is the push or pull on an object
• Contact forces are forces that act between two objects that are in contact with each other.
• non contact forces are forces that do not involve the direct contact of two objects.
• balanced forces are forces that are equal and opposite in magnitude and direction.
• unbalanced forces are when the force is not evenly distributed across the object
• Friction, upthrust, air resistance are examples of contact forces
• Magnetic and gravitational forces are non contact forces
• A balanced force will result in no movement or change in motion
• An unbalanced force will cause an acceleration or deceleration
• The weight of an object is the force exerted by gravity on it
• Upthrust is the upward force exerted by a fluid such as water or air on an object submerged in it
• Air resistance is the frictional force that opposes the motion of objects through the air
• Friction is the resistive force between two surfaces moving relative to one another
• Drag is the force acting against the forward motion of an object due to its shape, size and speed
• To reduce friction you can use lubricants, reduce surface area, or increase the speed of the object