CAIE A-Level Physics 1.4 Scalars and Vectors
Practise classifying quantities, combining coplanar vectors and resolving vectors into perpendicular components.
- Syllabus
- 2028–2030
- Course
- Physics 9702
- Level
- AS
Practise classifying quantities, combining coplanar vectors and resolving vectors into perpendicular components.
A property of a vector quantity, that is not a property of a scalar quantity, is direction. For example, velocity has direction but speed does not.
State two other scalar quantities and two other vector quantities.
scalar quantities: and vector quantities: and
two correct scalar quantities e.g. time, mass, distance, temperature
B1
two correct vector quantities e.g. force, acceleration, velocity, displacement
B1
A ship at sea is travelling with a velocity of 13 ms−1 in a direction 35∘ east of north in still water, as shown in Fig. 1.1.

Fig. 1.1
Determine the magnitudes of the components of the velocity of the ship in the north and the east directions.
north component of velocity = ms−1
east component of velocity = ms−1
north component of velocity =11 m s−1
A1
east component of velocity =7.5 m s−1
A1
The ship now experiences a tidal current. The water in the sea moves with a velocity of 2.7 ms−1 to the west.
Calculate the resultant velocity component of the ship in the east direction.
resultant east component of velocity = ms−1
velocity =7.5-2.7
=4.8 m s−1
A1
Use your answers in (b)(i) and (b)(ii) to determine the magnitude of the resultant velocity of the ship.
magnitude of resultant velocity = ms−1
velocity =(112+4.82)
C1
=12 m s−1
A1
Use your answers in (b)(i) and (b)(ii) to determine the angle between north and the resultant velocity of the ship.
angle = ∘
angle =tan−1(4.8/11)
C1
=24∘
A1
A car travels in a straight line up a slope, as shown in Fig. 3.1.

Fig. 3.1
The car has mass 850 kg and travels with a constant speed of 9.0 ms−1. The car's engine exerts a force on the car of 2.0 kN up the slope.
A resistive force FD, due to friction and air resistance, opposes the motion of the car.
The variation of FD with the speed v of the car is shown in Fig. 3.2.

Fig. 3.2
Consider the forces that act along the slope. Use data from Fig. 3.2 to determine the component of the weight of the car that acts down the slope.
FD=0.40(kN) or 0.40×103( N)
C1
component of weight =2.0×103−0.40×103=1.6×103 N
A1