2025.02

Exam Information

• Date: Tuesday, February 18

• Content: All class topics covered prior to the exam

• Format: 50% quantitative (calculations), 50% qualitative (concept understanding)

• Multiple Choice: Bring a pencil

• Tools: Scientific calculator only (no phones/electronics)

• Resources: Equation sheet provided, no personal notes or books allowed

Review Topics

Example Problems

• Skydiver Scenario:

  • A 95 kg skydiver accelerating downwards at 4.0 m/s²

  • Calculate net force and understand why it's not zero

  • Find force of air friction

• Pizza Throwing Example:

  • A 1.5 kg pizza thrown with a force of 67 N

  • a) Calculate weight of pizza.

  • b) Determine unbalanced (net) force.

  • c) Calculate acceleration (g = 9.80 m/s²)

Gravity Concepts

• Misconception: "There is no gravity in space" (False)

• Satellites: Orbit above Earth's atmosphere, in gravitational field.

Forces in Motion

Block Force Interactions

• Action and Reaction:

  • Blocks' forces on each other are equal.

• Force Diagrams:

  • Pulling a block with force F at an angle queries force relations (draw diagrams).

Hockey Pucks Example

• Two pucks pushed with equal forces, one of mass m and the other 4m.

  • Determine which puck crosses the finish line first: lighter puck wins.

Laws of Motion

Newton’s 3rd Law

• Actions and reactions occur in equal magnitude, opposite direction

• No exceptions! E.g., a car pushing a truck experiences equal and opposite forces.

Frictionless Surfaces

• Concept of pulleys and lifting weights at constant speed evaluates force exerted.

Chapter Topics: Momentum

• Key Concepts: Impulse and momentum, conservation of momentum, Newton's laws in action.

• Momentum Formula: p = mv (momentum = mass × velocity)

• Important Units: p = kg m/s (not a special unit)

• Total momentum in a system is conserved.

Sample Problems

• Calculate momentum of a running woman (mass = 60 kg, velocity = 2.0 m/s).

• Analyze effects on momentum based on various mass and velocity scenarios.

Hitting the Ball in Sports

• Maximizing momentum through force and time: F∆t=∆(mv)

• Skills like 'following through' can enhance ball hitting performance.