State what is meant by the centre of mass of a body.
A gymnast performs a high jump over a horizontal bar set at a height of 2.1 m2.1\text{ m}2.1 m above the ground. The maximum increase in gravitational potential energy (g.p.e.\text{g.p.e.}g.p.e.) of the gymnast during the jump is calculated using the expression:
Δg.p.e.=mgh \Delta \text{g.p.e.} = mgh Δg.p.e.=mghExplain why the value of hhh representing the vertical rise of the gymnast's centre of mass is significantly less than 2.1 m2.1\text{ m}2.1 m.
A gymnast performs a vault, starting from rest, running up, launching off a flexible springboard, clearing a vaulting table, and landing stationary on a safety mat.
Describe the energy changes that take place during this entire process, from the initial stationary position before the run-up to the final stationary position after landing on the mat.
229 exam-style questions on CIE IGCSE Physics 1.7.1a Energy stores and energy transfers. Each one has a worked solution and a mark scheme showing where the marks go.