2.4 Mechanics

Learning Intensions:

1. Calculate the average velocity of an object.

2. Use a = Δ v/Δt to calculate the acceleration of an object.

3. Interpret graphs relating to the motion of an object.

4. Use kinematic equations to solve problems involving instantaneous variables.

5. Describe the effect of gravity on an object's motion.

6. Describe variables as being either scalar or vector quantities.

7. Use vector addition to find the relative motion of objects.

8. Use vector subtraction to find changes in displacement, velocity and acceleration.

9. Describe the horizontal and vertical velocity of an object experiencing projectile motion.

10. Explain how the values found using the kinematic equations differ to the values found using v = Δd/Δt.

Learning Intentions:

1. Describe basic forces including, support, weight, thrust, friction (and/or tension).

2. Explain the difference between weight and mass.

3. Draw free-body force diagrams and use them to identify the net force acting on an object.

4. Use Newton's three Laws of Motion to describe the motion of an object.

5. Describe the velocity and acceleration of an object experiencing circular motion.

6. Explain how an object can have constant speed but still be accelerating.

7. Use the equation a = v^2/r to calculate centripetal acceleration.

8. Use Hooke's Law to solve problems concerning forces acting on springs.

9. Describe the concept of torque.

10. Use the equation 𝜏= Fd to calculate torque.

11. Define equilibrium, and discuss the conditions required for equilibrium.

12. Solve equilibrium problems.

Learning Intentions:

1. Describe and calculate kinetic energy, gravitational potential energy and elastic potential energy (stored in a spring).

2. Define and apply the principle of conservation of energy.

3. Solve conservation of energy problems that involve the equations for kinetic energy, gravitational potential energy and elastic potential energy.

4. Describe and calculate problems involving work.

5. Describe and calculate problems involving power.

6. Explain the concept of momentum and describe the quantities that affect momentum.

7. Define and apply the principle of conservation of momentum.

8. Use vector subtraction to solve change of momentum problems.

9. Define the concept of impulse, and discuss the concept in relation to common safety mechanisms.

10. Relate change in momentum to impulse.

References and Resources:

• SciPad Level 2 Physics

• Hewitt, Paul G. (2006), Conceptual Physics, The High School Physics Program, Pearson Prentice Hall.

• Rutter, Chris (2017), Physics NCEA Level 3 Workbook, ABA Resources Ltd.

• Hook, George (2000), NZ Pathfinder Physics Year 13, New House Publishers Ltd.

• Year 12 Physics Study Guide, ESA Publication (NZ) Ltd.

• NZ website: LearnCoach - Level 2 Physics - Mechanics

• NZ website: No Brain Too Small - Level 2 Mechanics

• Website: The Physics Classroom

• Website: Khan Academic - Physics

• Website: Bozeman Science - Physics