Edexcel A-Level Physics Resultant Vectors

Practise Edexcel A-Level Physics resultant vectors through scaled vector diagrams, perpendicular components, Pythagoras, bearings and resultant force or velocity directions.

Exam points

construct scaled vector triangles with arrows to find resultant force, momentum or displacement
use Pythagoras and trigonometry to calculate resultant magnitudes and angles
combine perpendicular components before choosing the correct resultant expression

[Maximum number: 4]

P and Q are identical spheres. Sphere P moves along a smooth horizontal surface and collides with sphere Q, which is initially stationary.

After the collision:
- sphere P moves off with a momentum of $0.096 \mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}$ in a direction of $15^{\circ}$ to its initial direction.
- sphere Q moves off with a momentum of $0.14 \mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}$ in a direction of $10^{\circ}$ as shown.

Figure for Question 1.3.6 - Resultant vectors question 1 — Edexcel A-Level Physics AS

Use a scaled vector diagram to show that the magnitude of the total momentum of spheres P and Q after the collision is about $0.2 \mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}$ .

Construction of correct vector diagram (parallelogram or triangle) with all 3 directions and $0.096\left(\mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}\right)$ and $0.14(\mathrm{~kg}$
(1)
$\mathrm{m} \mathrm{s}^{-1}$ ) labelled
- Momenta correctly scaled (ratio of lengths 0.14 to 0.096 rounds
to between 1.40 and 1.50)
)
- Horizontal resultant (to within a slope of 1 small square)
- Total momentum =0.22 to $0.24\left(\mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}\right)$
(Do not award MP4 if this value has been obtained by
calculation or from an incorrect diagram)

All question bank results loaded

1.3.6 - Resultant vectors question 1