This is a suggested answer to the GCE O Level Pure Physics examination, year 2013, Paper 1, multiple choice question 6.
The questio.n stated that a swimmer jumped into a deep pool and the following information were provided:
- Mass of swimmer =60kg
- deceleration in the water =16 m/s2
- gravitation field strength=10N/kg
The student is required to compute the Weight and Resultant Force of the swimmer.
Answer is C. That is, Weight =600N, Resultant Force=960N.
When the swimmer jumps into the water, her weight is:
W=mass x gravitational field strength
= 60kg x 10N/kg
When the swimmer is in the water, the water resistance is a frictional force, known as drag, that opposes her downward motion and cause her to decelerate. The resultant force is given by:
Resultant Force, F = Mass x acceleration
= 60 kg x 16 m/s2