A student investigates the motion of descending toy parachutes.
The student constructs a toy parachute with a lightweight plastic canopy. They drop the parachute from the top of a high stairwell, and then repeat the experiment by attaching different numbers of identical steel washers to the harness to vary the mass.
Name two measuring instruments that the student would need for this investigation.
Identify the independent variable and the dependent variable in this investigation.
State one control variable (a factor that must be kept constant) to ensure a fair test.
The student prepares a table to record the results. What would be the two most appropriate column headings, including suitable units, for this table?
Suggest one way the student could improve the reliability of the measurements in this experiment.
The student notices that the parachute accelerates immediately after release and then reaches a constant speed.
Name the two vertical forces acting on the parachute as it falls, and state which force is larger whilst the parachute is still accelerating downwards.
Explain, in terms of forces, why the parachute first accelerates and then falls at a constant speed.