A skycopter or skydiver is falling through the air. The table below gives the values of the acceleration of the skydiver at various heights above the ground.
height / m200015001000500acceleration / m/s28.55.21.80 \begin{array}{|l|c|c|c|c|} \hline \text{height / m} & 2000 & 1500 & 1000 & 500 \\ \hline \text{acceleration / m/s}^2 & 8.5 & 5.2 & 1.8 & 0 \\ \hline \end{array} height / macceleration / m/s220008.515005.210001.85000Describe what is happening, during the descent from 2000 m to 500 m, to: (i) the acceleration of the skydiver, (ii) the speed of the skydiver.
The acceleration becomes zero at a height of 500 m. Use ideas about forces to suggest why this happens.
Below a height of 500 m, the skydiver opens a parachute. Further measurements show that the acceleration of the skydiver has a negative value. What does this mean is happening to the speed of the skydiver?
The skydiver has a mass of 80 kg. Calculate the resultant force on the skydiver at a height of 1500 m.
245 exam-style questions on CIE IGCSE Physics 1.5 Forces, covering 1.5.1a Forces, resultant force and motion, 1.5.1b Load–extension graphs and the spring constant, 1.5.1c Friction and drag, 1.5.1d Force, mass and acceleration, 1.5.1e Motion in a circular path, 1.5.2a Moment of a force, 1.5.2b Principle of moments and equilibrium, and 1.5.3 Centre of gravity and stability. Each one has a worked solution and a mark scheme showing where the marks go.