class 8 science chapter 12 Force and pressure keywords
Answers
• Force: a push or a pull on an object is called force. Force may impart motion to an object.
• it is applied on an object in the same direction add to one another.
• Magnitude: the strength of a force is usually expressed by its magnitude
• State of motion: The state of motion of an object is described by its speed and the direction of motion.
• Muscular Force: The force resulting due to the action of muscles is known as the muscular force.
• Contact Force: The force which is applied when it is in the contact with the object.
• Non-contact force: The force exerted on an object without touching it known as non contact force.
• Gravitational force: the attractive force of earth which acts upon all the objects is called force of gravity or gravitational force.
• Pressure: The force acting on a unit area of a surface is called pressure. It acts perpendicular to the surface on which pressure is exerted.
• Pressure= force/area on which it acts. Lesser the area, greater is the force.
• Both liquids and gases exert pressure on the wall of their containers.
• Atmospheric pressure: The pressure on the atmospheric air is known as atmospheric pressure. This weight of air column over a unit 1cm2
Explanation:
- Atmospheric pressure
- contact force
- Electrostatic force
- Force
- friction
- Gravitational
- Gravity
- Magnetic force