Forces

• What are the two types of forces mentioned in the study material?

  Contact and Non-Contact Forces
• What do vectors have that distinguishes them from scalars?

  Vectors have magnitude and direction
• What is the force of gravity described as?

  The force of attraction between masses
• Why do we notice gravity primarily with large masses?

  Because they attract other masses strongly
• What happens to objects on the surface of a planet due to gravity?

  They fall towards the ground
• How is weight defined in relation to gravity?

  Weight is the force acting on an object due to gravity
• How does gravitational field strength vary?

  It varies with location and is stronger closer to the mass
• What is the difference between weight and mass?

  Mass is the amount of "stuff" in an object, while weight is the gravitational force on that object
• If a 1 kg mass weighs about 9.8 N on Earth, what would it weigh on the Moon?

  About 1.6 N
• How is weight measured?

  Weight is measured in newtons
• What is the center of mass of an object?

  It is the point where the mass is concentrated
• How is mass measured?

  Using a calibrated spring balance
• What happens when a force is applied to an object?

  It may stretch, compress, or bend the object
• What is elastic deformation?

  When an object returns to its original shape after the force is removed
• What is the spring constant?

  It depends on the material being stretched
• What is the equation for the force applied to a spring?

  F = ke
• What does the limit of proportionality refer to?

  The maximum force above which extension is no longer proportional to force
• How do you calculate elastic potential energy stored in a spring?

  E = ½ke²
• What is a moment in physics?

  A moment is the turning effect of a force
• What is pressure defined as?

  Pressure is the force per unit area
• What is the formula for calculating pressure?

  P = F ÷ A
• How does pressure in a liquid change with depth?

  Pressure increases with depth due to the weight of the liquid above
• What is the formula for calculating pressure at a certain depth?

  p = hρg
• How do you calculate the change in pressure between two depths?

  By subtracting the pressure at the shallower depth from the pressure at the deeper depth
• What happens to atmospheric pressure as height increases?

  Atmospheric pressure decreases with height
• What is the difference between distance and displacement?

  Distance is a scalar quantity, while displacement is a vector quantity
• What does a distance-time graph represent?

  It shows the distance travelled by an object over time
• What does a flat section on a distance-time graph indicate?

  It indicates that the object is stationary
• What does the gradient of a distance-time graph represent?

  The gradient represents the speed of the object
• What does a curving-up curve on a distance-time graph indicate?

  It indicates that the object is speeding up
• What is terminal velocity?

  It is the constant speed an object reaches when the force of gravity is balanced by drag
• How does drag change with speed?

  Drag increases as speed increases
• What is the most important factor in reducing drag?

  Improving the shape of the object
• What does a curving-up curve indicate about an object's motion?

  It indicates that the object is speeding up.
• What does a curving-down curve indicate about an object's motion?

  It indicates that the object is slowing down.
• How can you find the speed of an object at a specific point on a curve?

  By finding the gradient of the tangent to the curve at that point.
• What happens to an object with no force propelling it along?

  It will always slow down and stop because of friction.
• In which direction does friction act in relation to movement?

  Friction always acts in the opposite direction to movement.
• What is the definition of friction?

  Friction is the resisting force to movement.
• What is required to balance the frictional force between two surfaces in contact?

  The frictional force must be equal to the drag force.