levo

Projectile Motion and Fluid Mechanics

Drag, streamlining and technology

  • 3 things to know
  • Component 1

Overview

Aerodynamics and hydrodynamics, drag and velocity, frontal cross-sectional area, streamlining after a turn, surface characteristics, drafting, wind tunnels, swimsuits and the polyurethane ban, dimpled golf balls and the javelin redesign.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

What are aerodynamics and hydrodynamics?

Key term

Define drag.

Key term

How does velocity affect drag?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What are aerodynamics and hydrodynamics?

    Model answer

    Aerodynamics is the study of how bodies move through air. Hydrodynamics is the study of how bodies move through water.

  2. 2

    Define drag.

    Model answer

    Drag is a force that opposes the motion of a body through a fluid such as air or water. Drag in air is called air resistance.

  3. 3

    How does velocity affect drag?

    Model answer

    Drag increases sharply with velocity, roughly with its square. A cyclist who doubles speed faces about four times the air resistance.

  4. 4

    How does frontal cross-sectional area affect drag?

    Model answer

    A larger frontal area pushes against more fluid, so drag increases. A cyclist crouched low over the handlebars presents a smaller area and faces less drag.

  5. 5

    What is streamlining?

    Model answer

    Streamlining is shaping a body or object so that fluid flows smoothly around it with little turbulence. A streamlined shape is long, narrow and tapered, like a teardrop.

  6. 6

    How does a swimmer create a streamlined position after a turn?

    Model answer

    The swimmer stretches both arms beyond the head, hands together, with the body long and straight. The narrow shape cuts frontal area and turbulence, so the push-off carries further.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

The Musculo-Skeletal System
Levers, Newton's Laws and Stability
The Respiratory System
The Cardiovascular System

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

The survey began in .
201520052012

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AThe training zone is 136 to 158 bpm.
BHeart rate reserve = (220 − 40) − 70 = 110 bpm.
CLower limit = (110 × 0.6) + 70 = 136 bpm.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Acceleration means a rise in velocity each second.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Projectile Motion and Fluid Mechanics, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.