6. Explain the concepts of instantaneous centre with figure.
7. Explain the following terms with respect to a simple harmonic motion

(a) amplitude (0) time period (0) frequency

8. How can we connect two springs in series? Draw a diagram. Stiffness of two springs are k, and
1൨. Then what will be the stiffness of the combined system in series? Arrive at the expression.
Part—B
Answer two questions from each SET

SET 1
Each question carries 10 Marks (2 X 10 = 20 Marks)

9. Concurrent forces 1, 3,5,7,9 and 1 114 are applied at the centre of regular hexagon acting towards
its vertices as shown in Fig. 3. Determine the magnitude and direction of the resultant.

1N 3N

110 5

Fig.3

10. A ball of weight 120N rests in a right angled groove, as shown in Fig.4. The sides of the
groove are inclined at an angle of 30° and 60° to the horizontal. If all the surfaces are
smooth, then determine the reaction Ra and 1൦ at the points of contact.

۱

(அ) ۳

36° 60°
9

Fig.4

H

೧