Answer :
To find the resultant force of two forces of 40 and 20 dynes, acting in the same direction at the same point on a body, you can sum the forces together:
1. Convert the forces to newtons since 1 dina is equal to 105 newtons:
- 40 dynes = 40 * 105 newtons
- 20 dynes = 20 * 105 newtons
2. Calculate the forces in newtons:
- 40 dynes = 4200 newtons
- 20 dynes = 2100 newtons
3. Add the forces together to find the resultant force:
- Resultant force = 4200 newtons + 2100 newtons
4. Calculate the resultant force:
- Resultant force = 6300 newtons
Therefore, the resultant force when two forces of 40 and 20 dynes act on a body in the same direction at the same point is 6300 newtons.