4.1.2
Vector Problems
Test your knowledge with free interactive questions on Seneca — used by over 10 million students.
Resolving Vectors
You need to be able to resolve vectors into two components. That means separating the vector into two parts, each part at right angles to the other.

Resolving into x and y components
- The vector shown here sits in the x and y plane.
- We can resolve this vector into two perpendicular components: vertical and horizontal.

Resolving into x and y components
- The x (horizontal) component is given by:
- Fx = F cos θ
- The y (vertical) component is given by:
- Fy = F sin θ
Resolving Along an Incline
For problems with an inclined plane (a slope), it can be useful to resolve forces along the direction of the slope and the direction perpendicular to the slope.

Inclined plane
- A particle sits on a plane inclined at an angle θ.
- The weight of the cube is W and acts vertically downwards.
- There are no other forces acting.

Resolve along plane
- The weight resolved along the plane is W sin θ, as shown by the triangle drawn.
- The direction of the force is shown by the direction of the arrow.

Resolve perpendicular to the plane
- The weight resolved perpendicular to the plane is W cos θ, as shown by the triangle drawn.
- The direction of the force is shown by the direction of the arrow.
Equilibrium
An object is in equilibrium if the resultant force acting on it is zero. An object in equilibrium may be stationary (still) or moving with constant velocity.

Multiple forces
- The resultant force on an object in equilibrium is zero.
- This occurs when the forces form a closed triangle.

Example
- The forces in the example form a closed triangle.
- Therefore the object is in equilibrium.
1Measurements & Errors
1.1Measurements & Errors
2Particles & Radiation
2.1Particles
2.2Electromagnetic Radiation & Quantum Phenomena
3Waves
3.1Progressive & Stationary Waves
3.2Refraction, Diffraction & Interference
4Mechanics & Materials
4.1Force, Energy & Momentum
5Electricity
5.1Current Electricity
6Further Mechanics & Thermal Physics (A2 only)
6.1Periodic Motion (A2 only)
6.2Thermal Physics (A2 only)
7Fields & Their Consequences (A2 only)
7.1Fields (A2 only)
7.2Gravitational Fields (A2 only)
7.3Electric Fields (A2 only)
7.4Capacitance (A2 only)
7.5Magnetic Fields (A2 only)
8Nuclear Physics (A2 only)
8.1Radioactivity (A2 only)
9Option: Astrophysics (A2 only)
9.1Telescopes (A2 only)
9.2Classification of Stars (A2 only)
9.3Cosmology (A2 only)
10Option: Medical Physics (A2 only)
10.1Physics of the Eye (A2 only)
10.2Physics of the Ear (A2 only)
10.3Biological Measurement (A2 only)
10.4Non-Ionising Imaging (A2 only)
10.5X-Ray Imaging (A2 only)
10.6Radionuclide Imaging & Therapy (A2 only)
11Option: Engineering Physics (A2 only)
11.1Rotational Dynamics (A2 only)
11.2Thermodynamics & Engines (A2 only)
12Option: Turning Points in Physics (A2 only)
12.1Discovery of the Electron (A2 only)
12.2Wave-Particle Duality (A2 only)
Jump to other topics
1Measurements & Errors
1.1Measurements & Errors
2Particles & Radiation
2.1Particles
2.2Electromagnetic Radiation & Quantum Phenomena
3Waves
3.1Progressive & Stationary Waves
3.2Refraction, Diffraction & Interference
4Mechanics & Materials
4.1Force, Energy & Momentum
5Electricity
5.1Current Electricity
6Further Mechanics & Thermal Physics (A2 only)
6.1Periodic Motion (A2 only)
6.2Thermal Physics (A2 only)
7Fields & Their Consequences (A2 only)
7.1Fields (A2 only)
7.2Gravitational Fields (A2 only)
7.3Electric Fields (A2 only)
7.4Capacitance (A2 only)
7.5Magnetic Fields (A2 only)
8Nuclear Physics (A2 only)
8.1Radioactivity (A2 only)
9Option: Astrophysics (A2 only)
9.1Telescopes (A2 only)
9.2Classification of Stars (A2 only)
9.3Cosmology (A2 only)
10Option: Medical Physics (A2 only)
10.1Physics of the Eye (A2 only)
10.2Physics of the Ear (A2 only)
10.3Biological Measurement (A2 only)
10.4Non-Ionising Imaging (A2 only)
10.5X-Ray Imaging (A2 only)
10.6Radionuclide Imaging & Therapy (A2 only)
11Option: Engineering Physics (A2 only)
11.1Rotational Dynamics (A2 only)
11.2Thermodynamics & Engines (A2 only)
12Option: Turning Points in Physics (A2 only)
12.1Discovery of the Electron (A2 only)
12.2Wave-Particle Duality (A2 only)
Practice questions on Vector Problems
Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.
- 1What is the correct equation for the horizontal force?Multiple choice
- 2What is the correct equation for vertical force?Multiple choice
- 3Resolving vectors:Fill in the list
- 4
- 5What is the resultant force at equilibrium?Multiple choice
Unlock your full potential with Seneca Premium
Unlimited access to 10,000+ open-ended exam questions
Mini-mock exams based on your study history
Unlock 800+ premium courses & e-books