Principle of Moments

Q.

A uniform meter scale of weight $W$ is kept in equilibrium when supported at the $60cm$ mark and a mass m of weight w is suspended at $90cm$ mark as shown in the figure. Which of the following is true?

1. $W$ = w

2. $W$ < w

3. $W$ > w

4. Data insufficient

Q.

The wooden door of a building is $3m$ broad. It can be opened by applying a force of $100N$ at the middle of the door. Calculate the least force which can open the door.

1. $55N$

2. $52N$

3. $60N$

4. $50N$

Q. Observe the below mentioned figure and calculate $x$ in such a way that the seesaw would be in equilibrium.

1. 5

Q.

When a boy weighing $20kg$ sits at one end of a $4m$ long see-saw, it gets depressed at this end. How can it be brought to the horizontal position by another boy weighing$40kg$?

1. By sitting at a distance of $1m$ from the centre on the side opposite to the first boy.

2. By sitting at a distance of $1m$ from the centre on the same side as the first boy.

3. By sitting at a distance of $2m$ from the centre on the side opposite to the first boy.

4. By sitting at a distance of $2m$from the centre on the same side as the first boy.

Q.

The wooden door of a building is $3m$ broad. It can be opened by applying a force of $100N$ at the middle of the door. Calculate the least force which can open the door.

1. $55N$

2. $52N$

3. $60N$

4. $50N$