A force F is applied on a body (which moves on a straight line) for a duration of 3 s. The momentum of the body changes from 10 g cm/s to 40 g cm/s. The magnitude of the force F is

To find the magnitude of the force F, we apply Newton's second law of motion, which states that force is the rate of change of momentum. The change in momentum (Δp) is calculated by subtracting the initial momentum from the final momentum: 40 g·cm/s - 10 g·cm/s = 30 g·cm/s. According to the impulse-momentum theorem, Δp = F × t, where t is the time duration. Substituting the given values, we get 30 g·cm/s = F × 3 s, which simplifies to F = 10 g·cm/s². In the CGS (centimetre-gram-second) system, the unit of force is the dyne, defined as 1 g·cm/s². Therefore, the magnitude of the force is 10 dynes. This calculation confirms that the force required to change the momentum by 30 units over 3 seconds is exactly 10 units in the corresponding system.