Physics

• What are forces capable of changing?

  Shape, speed, or direction
• Why is it important to show arrows on forces?

  To indicate the direction of the force
• In what unit are forces measured?

  Newtons (N)
• What is weight?

  A force due to gravity acting on mass
• How does friction act on moving surfaces?

  It opposes motion between the surfaces
• What is drag?

  A force caused by movement through air or liquids
• What is forward thrust?

  A force provided by an engine
• What is upthrust?

  An upward force on objects in water
• What are resultant forces?

  • Overall force acting on an object
  • Can be calculated by adding or subtracting forces
  • Determines motion of the object
• If a box has forces of 5N and 12N acting on it, what is the resultant force?

  7N to the right
• What happens if two equal forces of 10N act on a box?

  The resultant force is 0N
• What does a resultant force of 15N indicate?

  The box will move to the left
• How do resultant forces affect moving objects?

  They can cause acceleration or deceleration
• What is mass?

  How much matter makes up an object
• How is weight defined in physics?

  A force acting on matter due to gravity
• What is the equation relating weight and mass?

  Weight = mass × gravity
• If an astronaut has a mass of 75kg, what is their mass on Pluto?

  75kg
• What would be the mass of a 10kg dog on the moon?

  10kg
• How do you calculate weight on Earth for a mass of 60kg?

  Weight = 60kg × 9.81N/kg
• How would you calculate weight on Mars for a mass of 60kg?

  Weight = 60kg × 3.71N/kg
• What is the weight difference for a 50kg person between Pluto and Jupiter?

  Calculate using respective gravity values
• What factors are included in the table of data for planets?

  • Distance from the Sun in millions of km
  • Number of moons
  • Diameter in km
  • Average temperature in °C
  • Gravity in N/kg
  • Time to orbit the Sun in Earth years
• What are the key concepts of mass and weight in physics?

  • Mass is measured in kilograms
  • Weight is a force measured in Newtons
  • Weight depends on gravity acting on mass
• What are the three parts of an atom?

  Protons, neutrons, and electrons
• Where are protons and neutrons found?

  In the nucleus
• What is electric current?

  The flow of electric charge
• What unit is current measured in?

  Amperes (A)
• What is the purpose of a battery in a circuit?

  To provide a voltage (push) to move the current
• What is voltage?

  The potential difference between two points in a circuit
• How is voltage measured?

  Using a voltmeter connected in parallel
• What does Ohm's Law state?

  V = I R (Voltage = Current × Resistance)
• What is resistance?

  The opposition to the flow of current
• What unit is resistance measured in?

  Ohms (Ω)
• In a series circuit, how does current behave?

  It is the same throughout
• In a parallel circuit, how does voltage behave?

  It is the same across all branches
• What is a magnetic field?

  A region where magnetic forces act
• What do magnetic field lines show?

  The direction and strength of a magnetic field
• How do you increase the strength of an electromagnet?

  More coils, more current, or an iron core
• What is Hooke's Law?

  Extension is proportional to force applied until the elastic limit
• What is pressure?

  Force per unit area (P = F/A)