Sketching graphs for other objects

1
Sketching graphs for other objects

• How do you think the distance time graphs for the
  following objects will look?
• A rocket.
• A parachutist.
• A wind up toy.
• A balloon racer.

2
The rocket
Distance (m)

• We used a compressed air launcher to send the
  rocket straight up.
• We plotted the graph for the upward journey
  alone, considering ground level to be the point
  of origin.

Time (s)
Initially, the speed was high. The gradient at
the start should then be greatest
As it moves, gravity and air resistance makes it
slow down. The gradient should decrease with time.
At its greatest height, it stops momentarily so
at the very end, the gradient is zero.
3
The wind - up toy

• We wound the spring to its maximum before
  releasing the toy on the floor.
• We plotted the graph for its journey from its
  starting point until it had stopped moving.

The toy seemed to move with a constant speed for
quite some time at the beginning.
As the spring wound down, it was more obvious
that it was slowing down, but it stopped quite
abruptly
4
The balloon racer

• We blew up the balloon before releasing the toy
  on the floor.
• We plotted the graph for its journey from its
  starting point until it had stopped moving.

The racer seemed to start off quite slowly, but
its speed increased quickly.
It maintained a constant speed for quite some
time.
It slowed down very gradually until it stopped.
5
The parachutist

• Initially he will fall without his parachute.
• He will fall faster and faster.
• Once his parachute opens, he will start falling
  much more slowly.

When the parachute opened, it slowed down
suddenly and continued to move steadily away from
its original point
It stops moving when it hits the ground.
At the instant it was dropped, the speed was
zero. Then for the next few seconds it moved
faster and faster because of gravity.