weight,mass and gravity

• How can gravity be 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 negligible for small objects like apples?

  Because they have relatively low masses
• What is the gravitational field strength on Earth?

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

  1.6 newtons per kilo
• What does an object experience when it enters a gravitational field?

  A force of attraction
• How is weight defined in physics?

  As the force of attraction on an object
• How do you calculate an object's weight?

  Mass x gravitational field strength
• 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 happens to energy used to lift an object?

  It transfers to gravitational potential energy
• What is the formula for gravitational potential energy?

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

  Joules
• How do you convert 100 grams to kilos?

  Divide by 1000
• 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.
• what is centre of mass

  a force acting from a single point on the object
• complete:

  weight and mass are directly proportional