Rocket Flying (continued).
When the rocket takes off,
there is a large thrust from the engine but very
little drag
because the rocket is moving slowly and air
resistance is small.
The forces are unbalanced
(large upward
force, small downward force)
and so the rocket has a large acceleration
in the direction of the larger force
(upwards).
As the rocket gets faster,
the drag increases and acceleration decreases
until the thrust and drag are equal in
size.
Now the forces are balanced
and the rocket will continue with a constant
velocity.
The motion of the rocket is shown on the velocity - time graph below.
The red
curve shows acceleration changing from large to small.
The blue line shows constant
velocity.
The next page shows how to calculate forces and acceleration.
Headings Forces and
Motion Search Questions 
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