A boy pushes a 500kg box along a floor with a force of 2000N. If the velocity of the box is uniform, the co-efficient of friction between the box and the floor is
1
0.8
0.65
0.4
Correct answer is D
m = 500kg, W = mg = 500 × 10 = 5000N
F = 2000N
| μ | = | Force at constant velocity
weight |
= | 2000
5000 |
= | 0.4 |