Paper 2: Forces and Motion Flashcards
What is stationary on a distance-time graph
Straight line
What is stationary on a velocity-time graph
Touching bottom of the graph
What is constant speed on a velocity-time graph
Straight line
What is constant speed on distance-time graph
Diagonal line
What is accelerating on distance time graph
Exponential
What is accelerating on velocity time graph
Diagonal line
Describe the changing forces that effect an object as it falls and its speed changes
When first dropped GPE is at maximum
As the object falls GPE is gradually transferred to Kinetic Energy
The object accelerates as GPE and kinetic energy are stronger than air resistance
Eventually the force and air resistance will become the same due and due to newtons 3rd law it will maintain a terminal velocity
Resultant force is zero
Object at constant speed
What is the law to do with momentum
Conservation of momentum
The momentum before an event in a closed system is equal to the momentum after an event
Newton’s 3 laws
- An object will stay in rest or an object will stay in motion unless a force acts upon it
- Force= mass x acceleration
- For every action there is an equal an opposite reaction
Braking distance equation
Stopping distance = braking distance + thinking distance
Thinking distance
The distance traveled before the driver reacts and applies the brakes
Braking distance
The distance traveled while the brakes are being applied
What effects thinking distance
Alcohol, drugs, tiredness, age
What effects braking distance
road surface, weather, conditions of brakes
How do airbags, crumple zones and seat belts reduce injury in a car crash
Increase the time taken to slow down which means the force is spread over a longer amount of time
Average reaction time for an adult
0.2s-0.9s
What is Hooke’s law
The amount of weight added to the bottom of a spring and its extension are directly proportional UNTIL A CERTAIN POINT
Force and extension equation
Force = constant x extension
What do you call the point where after an object is stretched it becomes permanently deformed
Elastic limit of proportionality
When both clockwise and anti-clockwise moments are equal
An object is balanced
What would you call levers and gears in physics
Force multipliers
Why is there greater pressure on an object the deeper an object is in a fluid
More particles above pressing down on it
What causes upthrust
The pressure on the underside of an object is greater than that of the top of the object
Driving force
Force that allows vehicles to move
