Two plates of thickness 10 mm each are to be joined by a transverse fillet weld on one side and the resulting structure is loaded as shown in the figure below. If the ultimate tensile strength of the weld material is 150 MPa and the factor of safety to be used is 3, the minimum length of the weld required to ensure that the weld does NOT fail is _____________ mm (rounded off to 2 decimal places).} 
Step 1: Understanding the problem setup.
We are given two plates, each with a thickness of 10 mm, to be joined using a transverse fillet weld. The structure is subjected to a force of 5 kN. The ultimate tensile strength of the weld material is 150 MPa, and the factor of safety is 3.
Step 2: Formula for the weld strength.
The strength of the weld can be calculated using the formula: \[ {Weld Strength} = \sigma_{{weld}} \times A_{{weld}} \] where:
\( \sigma_{{weld}} \) is the ultimate tensile strength of the weld material (150 MPa),
\( A_{{weld}} \) is the throat area of the fillet weld. The throat area \( A_{{weld}} \) of a fillet weld is calculated using the formula: \[ A_{{weld}} = \frac{1}{2} \times {leg size}^2 \] For a standard fillet weld, the leg size is equal to the plate thickness (10 mm).
Step 3: Using the factor of safety.
The allowable weld strength is calculated by dividing the ultimate strength by the factor of safety: \[ \sigma_{{allowable}} = \frac{\sigma_{{weld}}}{{Factor of safety}} = \frac{150}{3} = 50 \, {MPa} \] The required weld strength to resist the applied force \( F \) (5 kN) is: \[ {Required weld strength} = F = 5 \, {kN} = 5000 \, {N} \] Step 4: Calculation of the minimum weld length.
The length of the weld required can be determined using the formula: \[ L = \frac{F}{\sigma_{{allowable}} \times A_{{weld}}} \] Substituting the known values: \[ L = \frac{5000}{50 \times \frac{1}{2} \times (10)^2} \] \[ L = \frac{5000}{50 \times 50} \] \[ L = \frac{5000}{2500} = 2 \, {m} = 20.0 \, {mm} \] Step 5: Conclusion.
The minimum length of the weld required to ensure that the weld does not fail is 20.0 mm, rounded to 2 decimal places.




Consider the mechanism shown in the figure. There is rolling contact without slip between the disc and ground. 
Select the correct statement about instantaneous centers in the mechanism.
The wheels and axle system lying on a rough surface is shown in the figure.

Each wheel has diameter 0.8 m and mass 1 kg. Assume that the mass of the wheel is concentrated at rim and neglect the mass of the spokes. The diameter of axle is 0.2 m and its mass is 1.5 kg. Neglect the moment of inertia of the axle and assume \( g = 9.8 \, \text{m/s}^2 \). An effort of 10 N is applied on the axle in the horizontal direction shown at mid span of the axle. Assume that the wheels move on a horizontal surface without slip. The acceleration of the wheel axle system in horizontal direction is \(\underline{\hspace{1cm}}\) m/s² (round off to one decimal place).

