 ## Find the y coordinate of centre of gravity of a 100mm × 150mm × 30mm T

| Find the y coordinate of centre of gravity of a 100mm × 150mm × 30mm T-section. A. 94.1 mm B. 50 mm C. 75 mm D. 67.5 mm Right Answer is: SOLUTION (i) Rectangle ABCD A1 = 100 × 30 = 3000 mm2 Y1 = 120 + 30/2 = 135 mm (ii) Rectangle EFGH …

## A small mass M hangs from a thin string and can swing like a pendulum.

| A small mass M hangs from a thin string and can swing like a pendulum. It is attached above the window of a car. When the car is at rest, The string hangs vertically. The angle made by the string with the vertical when the car has a constant acceleration is approximately. A. 1° …

## Two identical balls are moving towards each other with a velocity of 3

| Two identical balls are moving towards each other with a velocity of 30m/s. If the coefficient of restitution of impact is 0.72, then the velocity of balls after impact is A. 21.6m/s B. 18.9m/s C. 15.6m/s D. 14.2m/s Right Answer is: SOLUTION momentum conservation- m × 30 – m × 30 = mVA + …

## Which of the following is true for applicability of Lami’s theorem to

| Which of the following is true for applicability of Lami’s theorem to a system of forces? A. Coplanar forces B. Concurrent forces C. Coplanar and Concurrent forces D. Any type of forces Right Answer is: SOLUTION Lami’s theorem states that – If three forces coplanar and concurrent forces acting on a particle keep it …

## A circular ring of negligible thickness and radius 200 mm is rotating

| A circular ring of negligible thickness and radius 200 mm is rotating at 600rpm. If the mass of the ring is 20kg then calculate the rotational kinetic energy in joule. A. 395 B. 1580 C. 786 D. 3160 Right Answer is: SOLUTION Kinetic energy of the flywheel = I = Therefore, kinetic energy =

## A stationary ball of mass 3kg undergoes direct central impact with a b

| A stationary ball of mass 3kg undergoes direct central impact with a ball of mass 1 kg moving towards it with a velocity of 12m/s. If the impact is perfectly elastic, then calculate the velocity of 3kg ball. A. 5 m/s B. 10 m/s C. 6 m/s D. 12 m/s Right Answer is: SOLUTION …

## A block of 40N is lying on a horizontal plane. It just begins to move

| A block of 40N is lying on a horizontal plane. It just begins to move when the force applied is 20N. What is the angle of friction(degrees)? A. 40 B. 30 C. 26 D. 55 Right Answer is: SOLUTION Maximum friction force = 20N = Weight of body = 40N Angle of friction =

## Two forces of magnitude 100N and 150N are acting on a body of mass 5kg

| Two forces of magnitude 100N and 150N are acting on a body of mass 5kg. What is the maximum acceleration(in  )and the minimum acceleration (in  ) the body is subjected to? A. 50 and 10 B. 35 and 15 C. 35 and 25 D. 40 and 10 Right Answer is: SOLUTION Maximum force = …

## Which of the following is the category of forces acting on the legs of

| Which of the following is the category of forces acting on the legs of tripod stand? A. Coplanar forces B. Parallel forces C. Concurrent forces non- coplanar D. Concurrent forces – planar Right Answer is: SOLUTION The forces in the leg of tripod stand all pass through the same point. However, they are in …

## In plane truss, the number of members having zero force is Joint A F

| In plane truss, the number of members having zero force is A. 5 B. 1 C. 3 D. 4 Right Answer is: SOLUTION Joint A FAC = 0 Joint E FDE = 0 FEF = 0 So total 3 members.