đŠī¸ Dynamic Lift
What force allows an airplane to move upward?
Dynamic lift.
What is sedimentation?
The process of allowing particles suspended in a liquid to sink and settle by gravity.
What is volume?
The amount of space occupied by an object.
What does a balance scale compare?
A known weight with an unknown weight.
Which process depends directly on gravity to make particles settle?
A) Buoyancy
B) Sedimentation
C) Dynamic lift
D) Thrust
B) Sedimentation
What creates the higher air pressure underneath an airplane's wings?
The design of the wings as air moves around them.
What happens to sand particles when river water slows down?
They sink and settle because they are heavier than the water.
What happens when an object weighs more than the volume of liquid it displaces?
The object sinks.
How does a spring scale measure weight?
It measures the distance a spring moves in response to the weight.
An airplane is moving through the air, but its engines are not producing enough thrust. What will most likely happen?
A) It will continue producing sufficient lift indefinitely.
B) It will lose the speed needed to create sufficient lift.
C) Its wings will become heavier.
D) The air pressure will disappear.
B) It will lose the speed needed to create sufficient lift.
Why must an airplane move at high speed to create sufficient lift?
Because sufficient lift is produced when the airplane moves through the air at high speed.
What are particles that settle at the bottom called?
Sediment.
What is the force that causes an object to rise to the surface of a liquid?
Buoyancy.
What can affect the elasticity of a spring?
Temperature.
A stone and a plastic ball have the same volume. The stone sinks while the plastic ball floats. What is the most important difference?
A) Their color
B) Their volume
C) Their weight
D) The temperature of the water
C) Their weight
How do jet engines produce thrust?
By forcing exhaust from the rear of the engine at high speed.
Why does shaking a bottle of olive oil keep particles suspended?
The movement keeps the particles floating in the liquid.
Why does a plastic ball rise to the surface of the sea?
Its weight is less than the weight of the same volume of displaced water.
Why can a spring scale give different measurements in different locations?
Because gravitational force can vary depending on location.
A spring scale measures a 10 kg object as 9.95 kg in another location. What problem described in the reading explains this difference?
A) Temperature
B) Sedimentation
C) Variation in gravitational force
D) Buoyancy
C) Variation in gravitational force
What combination allows an airplane to defy gravity?
Thrust and dynamic lift.
Give two examples of how sedimentation is used in real life.
Cleaning drinking water and treating sewage.
Why is there more pressure below a floating plastic ball than above it?
Because pressure in a liquid increases with depth.
What is recalibration?
Remeasuring the spring's response to weight under local conditions before using the scale.
An engineer needs to measure weight very accurately and wants the measurement to remain reliable despite changes in gravitational force and temperature.
Which type of scale would be more appropriate according to the reading, and why?
A balance scale, because variations in gravitational force and temperature have the same effect on both the known and unknown weights, allowing the scale to give the same measurement.