Lesson 5 - Linear and Rotational Motion

• What is the focus of Science for Engineers-102?

  Understand fundamental scientific principles of mechanical engineering
• How do forces affect motion?

  Forces influence the motion of objects
• How are linear and rotational motion treated in physics and engineering?

  They are treated as separate frames
• What is linear motion?

  Motion along a straight line
• What happens when forces act on an object in linear motion?

  The motion follows a straight line
• How can forces act on each other?

  With, against, at 90°, or any angle
• What is rotational motion?

  Motion around a pivot point
• What causes an object to rotate?

  Forces acting at a distance from a pivot
• What is the angle at which force must act for rotation?

  90° to the distance
• What are the key concepts to understand different types of motion?

  Types of forces, Newton's Laws, Weight, Centre of gravity
• What are the types of forces?

  • Contact Forces
  • Applied Force
  • Normal Force
  • Friction Force
  • Tension Force
  • Spring Force
  • Air Resistance Force
  • Distance Forces
  • Magnetic Force
  • Electrical Force
  • Gravitational Force
• What are contact forces?

  Forces requiring physical contact
• What are distance forces?

  Forces that do not require contact
• What is Newton's first law of motion?

  A body remains at rest or constant speed unless acted upon
• What happens when a body is acted upon by a force?

  It accelerates or decelerates
• What is Newton's second law of motion?

  Force equals mass times acceleration
• What does Newton's third law state about forces?

  Forces are equal in magnitude and opposite in direction
• What is an example of Newton's third law?

  A book on a table experiences normal force
• What is the formula for weight?

  Weight equals mass times gravity
• How do you calculate the weight of a 1 kg object on Earth?

  $W =$$9.8 \text{ N}$
• How does weight vary on different planets?

  • Weight depends on gravity
  • Example for a 100 kg crate:
  • Mercury: 378 N
  • Venus: 860 N
  • Earth: 978 N
  • Mars: 372 N
  • Jupiter: 2290 N
  • Saturn: 905 N
  • Uranus: 777 N
  • Neptune: 1100 N
• What is the gravitational acceleration on Earth?

  9.78 N/kg
• What is the relationship between mass and weight?

  Weight changes; mass remains constant
• How does doubling the radius affect gravitational potential energy?

  It results in a quarter of the energy
• What unit is weight measured in?

  Newtons (N)
• What is the base unit for weight in the formula W = mg?

  kg·m/s²
• What is the gravitational force between masses?

  Always attracts
• What is the significance of the center of gravity?

  It is the point where weight is balanced
• How do contact and distance forces differ?

  Contact forces require touch; distance forces do not
• What is stable equilibrium?

  A state where an object returns to position
• What is unstable equilibrium?

  A state where an object moves away from position
• What are balanced forces?

  Forces that cancel each other out
• What does it mean to resolve a force?

  To break a force into components
• What is the formula for weight?

  w = mg
• What does the variable 'g' represent in the weight formula?

  The acceleration due to gravity
• If an object has a weight of 160g, what is its weight in Newtons?

  $1.568 \text{ N}$
• How do you find the component of a force in the X direction?

  Use $AB \cos 30$
• How do you find the component of a force in the Y direction?

  Use $-AB \sin 30$
• What does it mean if a system is NOT in equilibrium?

  There is a resultant force acting on it
• What does Newton's second law state?

  F = ma, where F is the resultant force