41.
Coefficient of friction is the

42.
Pick up wrong statement about friction force for dry surfaces. Friction force is

45.
If a rigid body is in equilibrium under the action of three forces, then

47.
A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span

49.
A number of forces acting at a point will be in equilibrium if

50.
In ideal machines