Section 1: Forces And Motion Flashcards
(19 cards)
Know and use the relationship between acceleration, velocity and time
Acceleration = Change In Speed/Time
Determine acceleration from the gradient of a velocity-time graph
Acceleration = Rise/Run
Determine the distance travelled from the area between a velocity-time graph and the time axis.
The area under a Velocity time graph is equal to the distance travelled.
Identify different types of force
Kinetic, Potential, Electrical, Nuclear, Light, Sound and Heat
Distinguish between vector and scalar quantities
Vector: Has a Quantity and a Direction
Scalar: Has a Quantity but No Direction
Know and use the relationship between unbalanced force, mass and acceleration
Force = Mass × Acceleration
Know and use the relationship between Weight, Mass and Gravity:
Weight = Mass × Gravity
Describe the forces acting on falling objects and explain why falling objects reach a terminal velocity
When dropped the object experiences massive acceleration due to gravity. This acceleration slows due to the air resistance balancing acting on the object with the gravity. Eventually the gravity is equal to the air resistance and the speed is constant.
Describe experiments to investigate the forces acting on falling objects, such as sycamore seeds or parachutes
Dropping parachutes from a given height; this shows us that gravity is acting on them. By increasing the size of the parachute and recording the results we can see that air resistance also has an effect on falling objects; plotting a graph should reveal that bigger surface area takes more time, from which we can infer that air resistance acts on the falling objects.
Describe the factors affecting vehicle stopping distance including speed, mass, road condition and reaction time
The higher the speed the longer the stopping distance
The heavier the vehicle the longer the stopping distance
If the road is damp the stopping distance increases
The longer the reaction time (due to alcohol tiredness ECT), the longer the stopping distance
Know and use the relationship between momentum, mass and velocity:
Momentum = Mass × Velocity
Use the idea of momentum to explain safety features
Airbags: Rapidly expand in order to slow people down and don’t allow them to hit the surfaces of the car
Seatbelts: Hold people in place so they don’t fly forewords during a crash
Crumple Zones: Slow the car down rather then stopping it all at once
Use the relationship between force, change in momentum and time taken
Force = Change in Momentum
Demonstrate an understanding of Newton’s third law
Newton’s Third Law is: “For every action, there is an equal and opposite reaction.”
Know and use the relationship between the moment of a force and its distance from the pivot:
Moment = Force × Distance
Recall that the weight of a body acts through its center of gravity
The weight of a body acts through its center of gravity, at this point the weight is equally dispersed in all directions
Describe experiments to investigate how extension varies with applied force for helical springs, metal wires and rubber bands
Clamp a spring to a clamp stand. Put weight on spring. Measure extension of the spring. Repeat with different weight. Use F=KE to work out spring constant
Describe elastic behavior as the ability of a material to recover its original shape after the forces causing deformation have been removed.
Materials can return to there original shape once tension is released until they reach there limit of elasticity
Describe experiments to investigate the motion of everyday objects
Find a 1 meter ramp
Find a wheeled trolley
Let the trolley roll down the ramp and time the time taken for it to reach the bottom. Repeat this with a different angle each time
