Question

A rolling desk chair has a mass of 8 kg and an initial velocity of 6 m/s. The chair is given an acceleration of 12 m/s² for 3s.

What is the magnitude of the net force on the chair during acceleration?
96 N

48 N

144 N

288 N

Answer 1

Net force = 96 N

Step-by-step explanation:

Given:

Mass m = 8 kg

Initial velocity = 6 m/s

Acceleration a = 12 m/s²

Time = 3 s

Find:

Net force

Computation:

v = u + at

v = 6 + (12)(3)

v = 42 m/s

Work down = (1/2)(8)(42² - 6²)

Work down = 6,912

s = ut + (1/2)(a)(t)²

s = (6)(3) + (1/2)(12)(3)²

s = 18 + 54

Displacement (s) = 72 m

Net force = Work down / Displacement

Net force = 6,912 / 72

Net force = 96 N