Advertisements
Advertisements
प्रश्न
A cricket ball is thrown up from the earth's surface. What happens to its P.E.
(a) during the motion
(b) at the highest point?
उत्तर
(a) As the height above the ground increases, the potential energy also increases.
(b) At the highest point, the height of the cricket ball is maximum and hence the potential energy is also maximum.
APPEARS IN
संबंधित प्रश्न
Work done by a boy depends on the time in which he does work.
Power spent by a body depends on the time for which it does work.
A box of weight 150 kgf has gravitational potential energy stored in it equal to 14700 J. Find the height of the box above the ground. (Take g = 9.8 N kg-1)
In which of the following case the work done by a force will be maximum : when the angle between the direction of force and direction of motion is 0° or 90°?
Why is the work done on an object moving with uniform circular motion zero?
The velocity of a car increases from 54 km/hr to 72 km/hr. How much is the work done if the mass of the car is 1500 kg?
Nm is the unit of .......
What is the work done when the object acted upon by a force remains at rest?
On what factors does the work done by a force depend?
Distinguish between work and power.
Complete the following sentences:
1 H.P. = ........ W.
A weight lifted a load of 200 kgf to a height of 2.5 m in 5 s. calculate: (i) the work done, and (ii) the power developed by him. Take g= 10 N kg-1.
A boy of mass m climbs up a staircase of vertical height h.
- What is the work done by the boy against the force of gravity?
- What would have been the work done if he uses a lift in climbing the same vertical height?
Can work done be zero even if force acts on the body?
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
Fill in the boxe to show the corresponding energy transformation.
State the energy changes which take place when An electric bulb glows when it is connected to a source of electric current.
Is power a scalar or a vector quantity?
What is work?