Problem 2.11a Loci of Points – A circular disc of 72 mm diameter rotates about its center in the clockwise direction. While the disc completes one revolution, an insect walks across the diameter of the disc. Plot the locus of insect, assuming both the rotation of disc and movement of insect as uniform.

## Problem 2.10 Loci of Points

Problem 2.10 Loci of Points – In the figure given below, there is a horizontal channel PS which is fixed. And two rods PQ 80 mm long and QR 80 mm long glide in the channel PS such that the two rods are hinged at the point Q as shown in the figure below. Draw the locus of the midpoint of the rod QR.

## Problem 2.9 Loci of Points

Problem 2.9 Loci of Points – In a top view of a folding door mechanism, two rods PQ 110 mm long and QR 70 mm long are welded at the point Q. The angle PQR is 80°. The rod PQ is constrained to slide in a vertical and horizontal guide respectively as shown in the figure given below. For the motion of the rod AB vertically and horizontally, draw the locus of the point R and the point T; which is midpoint of the rod AB.

## Problem 2.8 Loci of Points

Problem 2.8 Loci of Points – In a four bar chain mechanism O1O2 is a fixed link. O1A 70 mm long is a driving crank, and the O2B 80 mm long is a driven crank and both the cranks are oscillating. The ends of both these links are connected with a link AB 60 mm long. And the initial position of the links are given in the figure below. Find the locus of the point P which is midpoint of the link AB.

## Problem 2.7 Loci of Points

Problem 2.7 Loci of Points – A four bar chain mechanism has a fixed link O1O2 130 mm long. The O1A 30 mm long is a driving crank revolving in clockwise manner. The driven crank O2B 60 mm long is oscillating about the center O2. The link AB 110 mm long is attached with the driving and driven crank. Draw the locus of the point P which is midpoint of the link AB.

## Problem 2.6 Loci of Points

Problem 2.6 Loci of Points – The figure given below shows an offset slider crank chain mechanism. The crank OA 40 mm long rotates in clockwise direction about the center O. The connecting rod AB 120 mm long is attached with the crank at the point A and the other end B is fixed in a slider EF 25 mm below the horizontal line passing through the point O, & the connecting rod AB is extended in the direction BA at the point L 35 mm from the point A as shown in the figure. Draw the loci points L & M; which is midpoint of the connecting rod AB for one complete revolution of the crank.

## Problem 2.5 Loci of Points

Problem 2.5 A circular disc of diameter 100 mm rotates about its center O for one revolution, during the rotation a point M which is at the point of the periphery of the disc moves to the center in a straight path when the disc completes the half revolution and then reaches back to its initial position in remaining half revolution of the disc. Draw the locus of the point M by assuming that the rotation of the disc and the motion of the point M are constant.

## Problem 2.4 Loci of Points

Problem 2.4 Loci of Points – A pendulum OC is pivoted at O is 120 mm long. It swings 300 to the right of vertical and also 300 to the left of vertical. An insect initially at O reaches to the point C, when the pendulum completes two oscillations. Draw the path of the insect, assuming motion of the insect and pendulum as uniform.