Force, Mass and Momentum
From ZuluNotes - Free Leaving Cert Notes
| Previous: | Newton’s laws of motion | Next: | Conservation of Momentum | Up: | Physics |
| Force, Mass and Momentum | |
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| Subject: | Physics |
| Paper | 1 |
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| Level | H&O |
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Contents |
Force
- A Force is anything which can cause an object to accelerate
- The unit of force is the Newton (N)*.
Mass
- The Mass of an object is a measure of how difficult it is to accelerate that object.
- This can also be defined as "The Mass of an object is a measure of its Inertia" - whereby the inertia is a measure of how difficult it is to accelerate it
- The unit of mass is the Kilogram (kg).
Relationship between Force, Mass and Acceleration
- Force = Mass × Acceleration
- F = ma
- An unbalanced force produces an acceleration
Weight
- The weight of an object is a measure of the force of the Earth’s gravity acting on it.
- Weight = Mass × Acceleration due to gravity
- W = mg
- Because weight is a force, the unit of weight is also the Newton.
Momentum
- Momentum = Mass x Velocity
- p = mv
- The Unit of Momentum is the kilogram metre per second (kg ms
).
Friction
- Friction is a force which opposes the relative motion between two objects
Examples of Friction
- Brakes
- Walking
- Air Resistance
