Motion + Pressure Flashcards
(15 cards)
What is speed?
Speed is how far something moves in a certain time.
Speed is measured in metres per second (m/s).
How is speed calculated?
speed (m/s) = distance travelled (m) / time taken (s)
Distances should be converted to metres and times to seconds.
What does relative motion compare?
Relative motion compares how fast one object is moving to another.
If two objects are moving at the same speed in the same direction, their relative speed is zero.
What does a distance-time graph show?
A distance-time graph shows the distance something travels over a certain time.
Average speed can be calculated from this graph by dividing distance covered by time taken.
What is pressure in solids?
Pressure in solids is the force applied on a surface divided by the area of that surface.
(Pressure = force ÷ area)
How is pressure calculated?
pressure (N/m²) = force (N) / area (m²)
This explains practical applications like why studded boots grip grass.
What produces gas pressure?
Gas pressure is produced by collisions between gas molecules and their container.
Compressing a gas increases collisions and thus pressure.
What happens to gas pressure when it is heated?
When a gas is heated, particles have more energy, move quickly, and collide more often with the container, increasing pressure.
What is atmospheric pressure?
Atmospheric pressure is the pressure acting on us from the air around us.
It decreases the higher you go above sea level due to less dense air.
What is true about pressure in liquids?
Pressure at the bottom of a liquid is greater than at the top due to the weight of the liquid above pushing down.
What are moments in physics?
Moments are the turning effect of a force,
Calculated as moment (Nm) = force (N) × perpendicular distance from the pivot (m).
What is the law of moments?
During equilibrium, all clockwise moments must equal all anticlockwise moments.
This principle helps explain how see-saws balance.
What causes objects to float?
Objects float because of upthrust, which is produced by liquid pressure.
Upthrust must be stronger than the forces acting on the top of the object.
Fill in the blank: Pressure is measured in _______.
newtons per metre squared
Fill in the blank: The unit for moment is _______.
newton metres
