Advertisements
Advertisements
Question
State the conditions of equilibrium for a rigid body.
Solution
Conditions of equilibrium for a rigid body:
1. The body should have a broad base.
2. Center of gravity of the body should be as low as possible.
3. Vertical line drawn from the center of gravity should fall within the base of
support.
4. Vector sum of forces acting on the body should be zero.
5. Algebraic sum of moments acting on the body should be zero.
APPEARS IN
RELATED QUESTIONS
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?
An electron emitter must have _____________ work function and ___________ melting point.
A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of the force. What should be the value of θ to get the maximum positive work?
When is work said to be done by a force?
Name the forms of energy which a wound-up watch spring possesses.
.A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s. Compare:
(i) the work done, and
(ii) the power developed by them.
The work done on an object does not depend on the :
If an electric bulb of 100 watt is lighted for 2 hours, how much electric energy would be consumed?
(a) Define power and name its unit.
(b) A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
Fill in the boxe to show the corresponding energy transformation.
Give an example
Light energy changes to electrical energy.
Define force. Is force a scalar or a vector quantity?
How long should an electric motor, of power 2 H.P. operate, so as to pump 5 m3 of water from a depth of 15m. [Take g = 10 N kg−1]
Mention whether work is done or not in the following activity.
| S. No | Activity | Work done or not done |
| 1. | Pushing the door | |
| 2. | Holding a doll | |
| 3. | Sitting in a bus | |
| 4. | Pushing a wall | |
| 5. | Digging soil |
A ______ should act on an object.
