A particle of mass 2.5 kg is moving at a speed of 12 m/s. If a force of magnitude 10 N acts against it, find how long it takes to come to rest.

To find the time it takes for the particle to come to rest, we can use the formula: time = (initial velocity) / (deceleration) where the deceleration is the rate at which the particle's velocity decreases due to the force acting against it. The deceleration can be calculated using Newton's Second Law, which states that force is equal to mass times acceleration: force = mass x acceleration Rearranging this formula, we get: acceleration = force / mass Substituting the given values, we get: acceleration = 10 N / 2.5 kg = 4 m/s^2 Therefore, the time it takes for the particle to come to rest is: time = 12 m/s / 4 m/s^2 = 3.0 s So, the answer is 3.0 s.