Force and motion

• what is a a scalar quanity?

  a quantity that has magnitude (size) only
• examples of scalar quantities 


  Sped,distance,Mass,energy
• what is a vector quantity?


  A quantity with magnitude (size) AND direction
• examples of vector quantities

  Displacement,velocity,forces,acceleration
• why is velocity different to speed?


  velocity also has a direction
• speed equation 


  speed (m/s)=distance(m)/time(s)
• what does a flat line on a distance time graph represent?


  a stationary object
• describe how you can determine the speed of an object from a distance time graph

  Change in y/change in x

  (gradient of a line)
• What does a steeper line represent on a distance time graph?


  Faster speed
• acceleration equation


  Acceleration(m/s^2)=change in velocity(m/s)/time(s)
• what does a flat line on a velocity time graph represent?


  constant velocity (speed)
• Describe how acceleration is determined on a velocity time graph 


  Change in y/change in x (gradient of a line)
• describe how Total distance travelled is determined on a velocity time graph 


  Area under the graph
• state the value for acceleration due to gravity on earth


  10 m/s^2
• state Newton’s first law


  an object remains at constant speed and direction if no external force acts on it
• state Newton’s second law


  force(n)=mass(kg)xacceleration(m/s^2)
• define weight


  the force on an object due to gravity (gravitation field strength E.g earth =10N/kg)
• describe what happens to the wieght of an object if the gravitational field strength increases


  the weight will increase
• describe how you could experimentally determine the relationship between force,mass and acceleration (CORE PRACTICAL!)


  attach masses to a trolley using string and hang masses of the edge of a table. measure a distance for the trolley to travel. release the masses and record the time taken for the trolley to travel the measured distance. use distance and time to calculate speed,then use speed and time to calculate acceleration. calculate force by multiplying mass by acceleration due to gravity (10N/kg). repeat for different masses. plot a graph of force against acceleratio.
• state newtons third law

  two interacting objects exert equal an opposite force on each other