An object travels 7.5 m/s toward the West and under the influence of a constant net force of 5.2 kN,it comes to rest in 3.2 s.What is its mass?
A) 1600 kg
B) 12000 kg
C) 1100 kg
D) 690 kg

Question

Quizplus · Accepted Answer

We can use the equation Fnet = ma, where Fnet is the net force, m is the mass, and a is the acceleration.
Since the object comes to rest, its final velocity is 0 m/s. Therefore, we can use the equation vf = vi + at, where vf is the final velocity, vi is the initial velocity, a is the acceleration, and t is the time.
Thus, 0 m/s = 7.5 m/s + a(3.2 s) 
Solving for the acceleration, we get a = -2.34375 m/s^2 (negative sign indicates that the acceleration is in the opposite direction of the initial velocity).
Plugging this value into Fnet = ma, we get 5.2 kN = m(-2.34375 m/s^2).
Converting kN to N and solving for m, we get m ≈ 1101 kg.
Therefore, the best choice is C.

An Object Travels 7