Physics P2: Forces Topic Summary
- Created by: Caitlin1602
- Created on: 11-02-18 15:06
View mindmap
- Physics - P2 ~ Forces
- Newton's Laws
- If there is no resultant force...
- Newton's Third Law- For every action there is an equal and opposite reaction
- Forces come in pairs
- Forces in an interaction pair; Are the same size, act on two different objects and act in two opposite directions
- Forces come in pairs
- Newton's Third Law- For every action there is an equal and opposite reaction
- If there is a resultant force...
- Newton's Second Law- An object accelerates (there is a change in speed)
- Newton's Third Law- For every action there is an equal and opposite reaction
- Forces come in pairs
- Forces in an interaction pair; Are the same size, act on two different objects and act in two opposite directions
- Forces come in pairs
- If there is no resultant force...
- Forces
- E.g- Friction, weight, drag, reaction & upthrust
- Measured in 'N'
- Can be contact/non contact
- Shown force arrow indicating size & Direction
- Free body diagrams
- Forces on leaf from two different pairs
- Initially- Force of Earth on leaf (down), non-equilibrium
- After a while- Force of air on leaf (up), force of Earth on leaf (down). Equilibrium & terminal velocity
- Forces on leaf from two different pairs
- Momentum
- Momentum is conserved
- Momentum before = momentum after
- E.g- Friction, weight, drag, reaction & upthrust
- Motion
- Speeds are found if you know distance (e.g. using a ruler) & time (e.g. using a stopwatch)
- Average speed (m/s) = Total distance (m) / time (s)
- Vector; has magnitude & distance. E.g. Distance & velocity
- Scalar; has magnitude only. E.g. distance & speed
- (Final velocity (m/s))^2 - (initial velocity (m/s))^2 = 2 x acceleration (m/s^2) x distance (m)
- Distance- Time Graphs, gradient gives you speed
- Velocity- Time Graphs, gradient gives you acceleration
- Accelration (m/s^2) = Change in speed (m/s) / change in time (s)
- Speeds are found if you know distance (e.g. using a ruler) & time (e.g. using a stopwatch)
- Forces In Action
- Moment (Nm) = Force (N) x distance (m)
- Clockwise moments = anticlockwise moments. Simple mechanisms (levers, pulleys) = Force multipliers
- Energy transferred in stretching (J) = 0.5 x spring constant (N/m) x extension (m)
- Force exerted by spring (N) = Spring constant (N/m) x extension (m)
- Gravity force (N) = Mass (kg) x gravitational field strength (N/kg)
- Weight (N) = Mass (kg) x gravitational field strength (N/kg)
- Gravitational potential energy (J) = mass (kg) x height (m) x gravitational field strength (N/kg)
- Moment (Nm) = Force (N) x distance (m)
- Newton's Laws
Comments
No comments have yet been made