Forces and Pressure Flashcards
What is force
A force is a push or pull acting on an object
What is the SI unit for force
newton (N) = kg metre per second square
What is force measured by
Spring balance or dynamometer
Effects of forces
1) Change in shape or size of an object
2) Change in direction or speed of moving object
3) Stop a moving object
4) Make a stationary object move
What is a contact force
A force that results when two interacting objects are in direct contact with each other
What is a non-contact force
A force applied to an object that is not in direct contact with it
What is frictional force
- Friction occurs when two objects are in physical contact with each other
- A force that acts in the opposite direction and opposes the motion of an object
5 advantages of friction
Daily activities, writing, holding on to objects, slowing down or stopping moving objects, moving across rough surface
2 Disadvantages of friction
Wear and tear, wastage of energy
Ways to overcome friction
Using lubricant oil or grease, using ball bearing rollers or wheels, using a cushion of air
What is gravitational force
Gravity is a force that pulls. It acts between two masses without direct in contact with each other
What is magnitude
The numeric quantity or value of something
What are factors that affect the magnitude of gravitational force
Mass of object, distance between two masses
Explain mass of object
-object with larger mass has greater gravitational force
Explain distance between two masses
-distance between two masses increases, gravitational force decreases
