CHAPTER 6. MOTIONIN TWO DIMENSIONS 6.5
(b) What is the magnitude of her velocity during her descent with
the parachute fully open?
The air resistance actingon the parachute is related to the speed
at which the parachutist descends. Graph B shows the relation-
ship between air resistance and velocity of theparachutist de-
scending with the parachute open.
0
100
200
300
400
500
600
700
800
900
0 1 2 3 4 5 6
Air resistance on parach
utist (N)
velocity (m·s−^1 )
Graph B
(c) Use Graph B to findthe magnitude of the air resistance on her
parachute when she was descending with the parachute open.
(d) Assume that the mass of the parachute is negligible. Calculate
the mass of the parachutist showing your reasoning clearly.
- An aeroplane travels from Cape Town and the pilot must reach Johan-
nesburg, which is situated 1300 km from Cape Town on a bearing
of 50◦in 5 hours. At the height at which the plane flies, a wind is
blowing at 100 km·hr−^1 on a bearing of 130◦for the whole trip.
50 ◦
Cape Town
Johannesburg
N
(a) Calculate the magnitude of the average resultant velocity of the
aeroplane, in km·hr−^1 , if it is to reach its destination on time.
