Statics and Dynamics

Forces of 3 N and 4 N act at right angles. What is their resultant?

1. 5 N
2. 12 N
3. 7 N
4. 1 N

For a rigid body to be in equilibrium:

1. The resultant force and the resultant moment must both be zero
2. Only the resultant force must be zero
3. It must be at rest on the ground
4. Only the resultant moment must be zero

A free-body diagram shows:

1. The body's velocity
2. The body's internal stresses
3. Only the weight
4. All the external forces acting on a body

A 6 m simply supported beam carries a 60 kN load at its centre. What is each support reaction?

1. 60 kN
2. 20 kN
3. 30 kN
4. 120 kN

A couple consists of:

1. A single force through the centre of mass
2. Two forces acting in the same direction
3. Two equal, opposite, parallel forces that do not act along the same line
4. Two forces meeting at a point

Lami's theorem applies to:

1. Fluids at rest
2. Three concurrent forces in equilibrium
3. Any number of parallel forces
4. Moving bodies

A block presses on a surface with a normal force of 200 N. The coefficient of friction is 0.3. What is the limiting friction force?

1. 600 N
2. 60 N
3. 200 N
4. 66.7 N