Final answer:
The magnitude of the object's velocity at the end of the 4-second interval is 32 m/s in the negative x-direction.
Step-by-step explanation:
In this situation, we can apply Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
Using the given information, we can calculate the acceleration of the object:
Mass (m) = 0.5 kg
Force (F) = -5 N
Acceleration (a) = F/m = (-5 N) / (0.5 kg) = -10 m/s²
Since the initial velocity is +8 m/s in the positive x-direction, and the acceleration is in the negative x-direction, the final velocity can be calculated using the kinematic equation:
v = u + at
Where v = final velocity, u = initial velocity, a = acceleration, and t = time.
Substituting the given values:
v = 8 m/s + (-10 m/s²)*(4 s) = 8 m/s - 40 m/s = -32 m/s
Therefore, the magnitude of the object's velocity at the end of the 4-second interval is 32 m/s in the negative x-direction.
The complete question is given below:
An object of mass 0.5 kg moves to the right with a velocity of +8 m/s. A force of -5 N directed to the left acts on the object for 4 s. What is the final velocity of the object?