Formative Assessment Grade 9

Formative Assessment            Grade: 9   Student Name ----------------------------Date:

 Working Towards:      Achieved               85%   Questions Correct   =   Success Criteria 

Unit: Physical Equilibrium Types

Learning Outcomes

Able to define stable, unstable and neutral equilibriums

Able to draw “free body” diagram examples for all three types of equilibrium

Show forces (annotate on diagrams) involved in all equilibrium conditions

(1)   What is meant by stable equilibrium   ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(2)   Draw a free body diagram for a pencil in stable equilibrium, indicate forces involved 

(3)   Define unstable equilibrium .  _______________________________________________________________________________________________________________________________________________________________________________________________________________

(4)     Draw a free body diagram for a pencil in unstable equilibrium, again indicate forces   involved.

(5)   Define Neutral Equilibrium  ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(6)    Draw diagram showing an object such as a ball in neutral equilibrium, show forces involved

Solutions To Formative Questions

(1)

When the center of gravity of a body lies below the point of suspension or support, the body is said to be in a state of stable equilibrium.  Or words effectively having the same equivalent meaning.

(2  )   

(3)  

When the center of gravity of a body lies above the point of suspension or support, the body is said to be in unstable equilibrium. Or words effectively having the same equivalent meaning.

(4) 

(5)  The center of gravity of a body lies at the point of suspension or support, the body is said to be in neutral equilibrium . Or words effectively having the same equivalent meaning.

(6)