This is an exam review question that I can't quite figureout: A block rests on a rough horizontal surface with thecoefficient of static friction 0.6 and coefficient of kineticfriction 0.3. A constant horizontal force just sufficient tostart the block in motion is applied. Once the block is inmotion, approximately what is the acceleration of the block inm/s^2? A)10 B)3 C)1 D)9 E)7 This is an exam review question that I can't quite figureout: A block rests on a rough horizontal surface with thecoefficient of static friction 0.6 and coefficient of kineticfriction 0.3. A constant horizontal force just sufficient tostart the block in motion is applied. Once the block is inmotion, approximately what is the acceleration of the block inm/s^2? A)10 B)3 C)1 D)9 E)7
Explanation / Answer
Force required to make object move F1 = s* m * g = 0.6 * m *9.8 = 5.88 *m N Force required to keep objectmoving F2 = k *m * g = 0.3 * m *9.8 = 2.94 *m N Net force working onobject F = F1 - F2 = 5.88* m - 2.94 * m = 2.94 * m Acceleration a = F/ m = 2.94 * m /m = 2.94 m/s2 ˜ 3 m/s2