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Two parallel, but not necessarily unidirectional, forces of magnitude 1 N and 2 N are acting on a body. Two more, parallel, again not necessarily unidirectional, forces of magnitude 3 N and 1 N, but perpendicular to the earlier forces, are applied to the body. Which one among the following are the smallest and largest possible magnitudes of the resultant force on the body ?
Explanation
The resultant of two parallel forces F1 and F2 depends on their relative direction: it is either |F1 + F2| (if unidirectional) or |F1 - F2| (if opposite).
- For the first set (1 N and 2 N), the possible resultants (R1) are 1 N (2 - 1) or 3 N (2 + 1).
- For the second set (3 N and 1 N), the possible resultants (R2) are 2 N (3 - 1) or 4 N (3 + 1).
Since the two sets are perpendicular to each other, the total resultant magnitude R is calculated using the Pythagorean theorem: R = √(R12 + R22).
- Minimum R: √(12 + 22) = √5 N
- Maximum R: √(32 + 42) = √25 = 5 N
The other combinations (√17 N and √13 N) fall between these values. Thus, the smallest and largest magnitudes are √5 N and 5 N.
SIMILAR QUESTIONS
Two forces of 5.0 N each are acting on a point mass. If the angle between the forces is 60°, then the net force acting on the point mass has magnitude close to :
Which of the following statements about a body under equilibrium is/are correct ?
1. No forces are acting.
2. A number of parallel forces may be acting.
3. The law of moments must apply.
Select the correct answer using the code given below :