The only force acting on a 2.0-kg object moving along the x axis is shown.If the velocity v_x is +2.0 m/s at t = 0,what is the velocity at t = 4.0 s? A)+4.0 m/s B)+5.0 m/s C)+6.0 m/s D)+7.0 m/s E)+2.0 m/s

Question

Quizplus · Accepted Answer

Since the force acting on the object is constant, we can use the kinematic equation: 
v = v0 + at

where v is the final velocity, v0 is the initial velocity, a is the acceleration, and t is the time interval.

Since there is no force acting on the object in the y-direction, we can ignore any motion in that direction and focus only on motion along the x-axis.

The force is in the positive x-direction, so the acceleration is also in the positive x-direction. Using Newton's second law, we can find the acceleration:

F = ma 
4.0 N = 2.0 kg * a 
a = 2.0 m/s^2

Now we can use the kinematic equation to find the final velocity:

v = v0 + at 
v = 2.0 m/s + (2.0 m/s^2) * (4.0 s) 
v = 10 m/s

However, we need to take into account the fact that the velocity is in the positive x-direction, so the answer should be:

Answer: A) +4.0 m/s

The Only Force Acting on a 2