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प्रश्न
A spanner (or wrench) has a long handle. Why?
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उत्तर
The long handle of the spanner creates a greater turning moment. The handles' ends are used with less force.
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संबंधित प्रश्न
Match the column
| Column A | Column B |
| (a) Camel | (1) broad and deep foundation |
| (b) Truck | (2) broad feet |
| (c) Knife | (3) six or eight tyres |
| (d) High building | (4) sharp cutting edge |
| (e) Thrust | (5) atm |
| (f) Moment of force | (6) N |
| (g) Atmospheric pressure | (7) N m |
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The stone of hand flour grinder is provided with a handle near its rim. Give reason.
A wheel of diameter 2 m is shown in the figure with the axle at O. A force F = 2 N is applied at B in the direction shown in the figure. Calculate the moment of force about
- the centre O, and
- the point A.

A uniform metre rule of weight 10gf is pivoted at its 0 mark.
What moment of force depresses the rule?
Classify the following amongst contact and non-contact forces.
magnetic force
Calculate the resultant moment of forces about O and state its direction in fig.

A person standing in front of a cliff fires a gun and hears its echo after 3 s. If the speed of sound in air is 336 ms−1.
- Calculate the distance of the person from the cliff.
- After moving a certain distance from the cliff, he fires the gun again, and this time the echo is heard 1.5 s later than the first. Calculate the distance that the person moved.
The diagram in Fig shows two forces F1 = 5 N and F2 = 3 N acting at points A and B respectively of a rod pivoted at a point O, such that OA = 2 m and OB = 4 m.

Calculate:
- the moment of force F1 about O.
- the moment of force F2 about O.
- total moment of the two forces about O.
