Forces and Matter

• What are the three types of deformation mentioned?

  Elastic, plastic, and linear elastic distortion
• What happens when a single force is applied to an object?

  The object moves in the force's direction
• What occurs when a spring is compressed from opposite sides?

  The spring compresses due to inward forces
• What is a reaction force in the context of a spring?

  Force from the fixed point opposing the applied force
• What does deformation mean?

  Changing shape of an object
• What is elastic deformation?

  The object returns to its original shape after load removal
• What is plastic deformation?

  The object does not return to its original shape after load removal
• What is the formula for Hooke's Law?

  F = kx
• What does the spring constant \( k \) represent?

  Force required to extend a spring per metre
• What do the variables \( F \), \( k \), and \( x \) represent in Hooke's Law?

  Force, spring constant, and extension respectively
• What does the gradient of a Force/Extension graph represent?

  The spring constant \( k \)
• What is the elastic limit of a spring?

  The point where it stops obeying Hooke's Law
• What characterizes a non-linear section on a Force/Extension graph?

  It does not follow Hooke's Law
• What happens if a material is brittle?

  It snaps instead of stretching after the elastic limit
• How is work done calculated in relation to a spring?

  Work Done = \( \frac{1}{2} kx^2 \)
• What is atmospheric pressure?

  Total weight of air above a unit area
• How does atmospheric pressure change with altitude?

  It decreases with increasing height
• Why does atmospheric pressure decrease with height?

  Fewer air molecules above the unit area
• What is a fluid?

  A liquid or a gas
• How does pressure in a gas depend on atmospheric pressure?

  It depends on the inward force exerted by air
• What happens to a balloon in space?

  It expands due to lower atmospheric pressure
• What effect does blowing into a balloon have?

  Increases pressure inside due to more collisions
• What does pressure in a fluid cause?

  A force perpendicular to any surface
• How does pressure vary with depth in a fluid?

  Greater depth results in greater pressure
• Why does pressure increase with fluid density?

  Greater density means greater weight of fluid
• What condition allows an object to float?

  Weight less than weight of displaced water
• How does a boat float in water?

  It displaces its weight in water
• What is buoyancy?

  The upward force counteracting the weight of an object
• How is buoyancy force determined?

  Equal to weight of fluid displaced
• Why does a ping pong ball float on water?

  Its density is less than that of water
• What happens to pressure as depth increases in a liquid?

  Pressure increases due to weight of water above
• What is the formula for pressure due to a column of liquid?

  Pressure = height × density × g