Engineering Mechanics

Question 1

Name and draw a diagram of all 3 beam support types:

Answer 1

1. Simply Supported Beam - Makes use of a pin and roller. (Pin at very edge, roller at opposite edge.
2. Overhanging Beam - Makes use of a pin and roller. (Pin at very edge, roller a bit off the edge.)
3. Cantilever Beam - Makes use of a wall support.

Question 2

An object is in equilibrium when:

Answer 2

Both the sum of all horizontal forces (ΣFH) = 0 and the sum of all the vertical forces (ΣFV) = 0.

Question 3

Concurrent forces are two or more forces:

Answer 3

Whose lines of action intersect at the same point to cause rotation; the forces do not necessarily have to be applied.

Applied forces: Push or Pull, Friction, Air-resistance.
Non-Applied forces: Gravity, Weight, Magnetic

Question 4

The magnitude of the moment can be thought of as the strength of the twisting force exerted on the body. The magnitude of a moment describes how hard it turns, in the same way that the magnitude of a force describes how hard it pushes or pulls. The moment force can be either clockwise or anticlockwise, depending on the direction of the force. What units are the magnitude of a moment force measured in?

Answer 4

Force times Distance (M = FD)
Base = NewtonsMeters. or Nm (Newton Meters)

Question 5

1. Calculate the spanner’s turning effect in Newtons (Force = 20N, Length = 20cm)
2. A 560 N force is applied at the end of the beam, 2 meters from the wall it is being held. Calculate the moment produced.

Answer 5

1. Convert 20cm into m, then multiply, 20N0.2M = 4NMeters
2. 560N*2m = 1120Nm

Question 6

Calculate the moment of the container that is being loaded onto the ship.
Crane is 18m long, Weight of crate being loaded is 45000N

Answer 6

1. 45000N18m = 810000Nm or 81kNm (kNm = Nm0.0001 (Divided by 10000)