Example (1): Finding the weight of a body

• A body of mass 5 kg rests on a horizontal surface. Find its weight, taking g = 10 m/s².
• Solution:

1. Weight = mass × g.
2. W = 5 × 10 = 50 N.
3. The weight acts vertically downwards.

Example (2): Two forces on the same straight line

• Two forces act on a body along the same horizontal line a force of 20 N to the right and a force of 15 N to the left. Find the resultant force and its direction.
• Solution:

1. 20 − 15 = 5 N.
2. The value is positive, so the direction is to the right.
3. The resultant is 5 N to the right.

Example (3): Three forces on one horizontal line

• Three forces act on a body along one horizontal line a force of 12 N to the east, a force of 4 N to the west, and a force of 8 N to the west. Find the resultant and state whether the body is in equilibrium.
• Solution:

Example (4): Finding the magnitude from a diagram

• An arrow 6 cm long represents a force, and the scale of the diagram is 1 cm for every 4 N. Find the magnitude of the force.
• Solution:

1. Magnitude = length of the arrow × scale.
2. Magnitude = 6 × 4 = 24 N.