A 10-kg object at rest is exposed to a constant net force of 50 N for 4 seconds. What is its velocity after 4 seconds?
A20 m/s
B5 m/s
C2.5 m/s
D200 m/s
Explanation
📌 Impulse = FΔt = 50 × 4 = 200 kg·m/s = Δp. Since starting from rest, p_f = 200 kg·m/s. v = p/m = 200/10 = 20 m/s. Distractor B: divided F by t; C: quarter of correct; D: forgot to divide by m.