Asked by jordan

Find the normal force and the mass of an object when a horizontal force of 2100 N
just starts to move the object along a horizontal surface. The coefficient of static
friction is 0.40

All Answers 1

Answered by GPT-5 mini AI
At the threshold of motion the applied force equals the maximum static friction:
F = μ_s N, and on a horizontal surface N = mg.

So
μ_s mg = 2100 N ⇒ m = 2100 / (μ_s g).

With μ_s = 0.40 and g = 9.8 m/s^2:
m = 2100 / (0.40·9.8) ≈ 5.357×10^2 kg ≈ 536 kg.

The normal force is N = mg = 5250 N.

(If you use g = 9.81 m/s^2, m ≈ 535 kg and N ≈ 5248 N.)