Gravitational Potential Energy & Gravity

• What is gravity defined as?

  A force of attraction between two objects
• What factors determine the size of the gravitational force?

  Mass of objects and distance between them
• Why is the gravitational force of small objects negligible?

  Because they have relatively low masses
• How does distance affect gravitational attraction for large objects?

  Gravitational attraction decreases with distance
• What is the gravitational field strength on Earth?

  Approximately 9.8 newtons per kilo
• What is the gravitational field strength on the Moon?

  Approximately 1.6 newtons per kilo
• What do we call the area around an object where gravity is felt?

  Gravitational field
• What is the relationship between weight and gravitational field strength?

  Weight equals mass times gravitational field strength
• How do you calculate the weight of a 60 kg person on Earth?

  60 kg times 9.8 newtons per kilo
• What is the weight of a person with a mass of 60 kg on Earth?

  588 newtons
• How do we typically refer to mass in everyday language?

  We say we weigh a certain number of kilos
• What is the difference between mass and weight?

  Mass is intrinsic; weight is a force
• What is required to lift an object against gravity?

  Energy or work
• What is the formula for gravitational potential energy?

  Ep = mgh
• What units are used for gravitational potential energy?

  Measured in joules
• How do you convert 100 grams to kilograms?

  Divide by 1000 to get 0.1 kg
• What is the gravitational potential energy of a 100-gram apple thrown 3 meters high?

  2.94 joules
• What are the key takeaways about gravity, weight, and gravitational potential energy?

  • Gravity is a force of attraction.
  • Weight = mass × gravitational field strength (9.8 N/kg on Earth).
  • Gravitational potential energy (Ep) = mass × gravitational field strength × height.